Si Units In Physics

Mechanics & Motion - Related Topics

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Analog Electronics
8

Analog electronics is a branch of electronics that deals with continuous signals, as opposed to digital electronics, which deals with discrete sign...

Magnetostatics Definition Properties Differences
4051

In magnetostatics, boundary conditions are used to describe the behavior of magnetic fields at the interfaces between different materials. These co...

Aberration Of Lens
4054

Lens aberration is a phenomenon that occurs when light rays passing through a lens do not converge at a single point, resulting in a distorted or i...

Absorption Spectrum
4055

An absorption spectrum is a graph that shows the amount of light absorbed by a substance as a function of the wavelength of light. It is a characte...

AC Circuit
4056

An alternating current (AC) circuit is a circuit in which the current periodically reverses direction. This is in contrast to a direct current (DC)...

AC Motor
4057

An AC motor is an electric motor that converts alternating current (AC) into mechanical energy. AC motors are widely used in industrial and commerc...

Acceleration Time Graph
4058

An acceleration time graph is a graphical representation of the acceleration of an object over time. It is a useful tool for analyzing the motion o...

Acoustics
4059

Acoustics is the science that deals with the production, control, transmission, reception, and effects of sound. It is a branch of physics that stu...

Adiabatic Demagnetization
4060

Paramagnetic materials are a class of materials that exhibit a weak attraction to magnetic fields. This attraction is caused by the presence of unp...

Advanced Sunrise And Delayed Sunset
4061

The rising and setting of the sun are daily phenomena that mark the beginning and end of each day. While we generally think of these events as occu...

Ammeter
4062

An ammeter is a measuring instrument used to measure the strength of an electric current in amperes. It is a device that allows the user to determi...

Anemometer
4064

An anemometer is a device used to measure wind speed and direction. It is commonly used in meteorology, climatology, and other fields that require ...

Angular Acceleration
4065

Angular acceleration is the rate at which an object's angular velocity changes. It is measured in radians per second squared (rad/s²).

Dynamic Lift
4067

Dynamic lift is a phenomenon that occurs when an object moves through a fluid, such as air or water. It is the force that acts perpendicular to the...

Layers Of Sun
4067

The Sun, our closest star, is a hot ball of glowing gases that emits vast amounts of energy. It consists of several layers, each with its unique ch...

LCR Series Circuit
4068

An LCR series circuit is a circuit that consists of an inductor (L), a capacitor (C), and a resistor (R) connected in series. The current in an LCR...

Effects Of Radiation
4069

Radiation is the emission or transmission of energy in the form of waves or particles. It can be classified into two main types: ionizing and non-i...

Lemon Battery
4069

A lemon battery is a simple electrochemical cell that uses a lemon as the electrolyte. It is a fun and easy way to demonstrate the principles of el...

Limitations Of Ohms Law
4072

Ohm's law is a fundamental principle in electrical engineering and physics that describes the relationship between voltage, current, and resistance...

Power Factor
4074

Power factor is a measure of how efficiently electrical power is used in an alternating current (AC) circuit. It is defined as the ratio of the rea...

Power In Ac Circuit
4075

In an alternating current (AC) circuit containing a pure resistor, the current and voltage are in phase, meaning they reach their maximum and minim...

Power Transformers
4076

Power transformers are essential components of electrical power systems, enabling the efficient transmission and distribution of electricity. Their...

Pressure Gauge
4077

A pressure gauge is a device used to measure the pressure of a fluid (liquid or gas) or gas. It is typically used in industrial and commercial sett...

Pressure Of An Ideal Gas
4078

The ideal gas law is a fundamental equation in physics that describes the behavior of gases under various conditions. It provides a mathematical re...

Pressure
4079

Pressure is a physical quantity that measures the force applied perpendicular to the surface of an object per unit area. It is a scalar quantity, m...

Principle Of Calorimetry
4080

A calorimeter is a device used to measure the amount of heat released or absorbed during a chemical reaction or physical change. It is an essential...

Electrolytic Capacitor
4081

Electrolytic capacitors are polarized capacitors that use an electrolytic solution as one of the plates. They are typically made of aluminum or tan...

Propagation Constant
4081

The propagation constant is a complex number that describes how a wave propagates through a medium. It is defined as the square root of the product...

Proton Mass
4083

The proton is a subatomic particle that is found in the nucleus of an atom. It is one of the three main types of subatomic particles, along with th...

Electron Spin
4084

Electron spin is a fundamental property of electrons, which is related to their intrinsic angular momentum. It is a vector quantity and can be eith...

Pulley System
4084

A pulley system is a mechanical device that consists of one or more pulleys and a rope or cable that runs through them. Pulleys are used to lift or...

Electronic Communication Systems
4085

A communication system is a collection of components that allows information to be transmitted from one place to another. In electronics, communica...

Pulse Width Modulation
4085

Pulse Width Modulation (PWM) is a technique used to control the power delivered to a load by varying the width of the pulses of a periodic waveform...

Electroscope
4086

An electroscope is a simple device used to detect the presence and type of electric charge. It consists of a metal rod with a small, lightweight ob...

Quantization
4086

Quantization is a process of converting a continuous signal into a discrete signal. This is done by dividing the continuous signal into a finite nu...

Electrostatic Precipitator
4087

An electrostatic precipitator (ESP) is a device that removes particulate matter from a gas stream by applying an electrical charge to the particles...

Electrostatics
4088

In electrostatics, boundary conditions are the conditions that must be satisfied by the electric field and the electric potential at the boundaries...

Radiation Pressure
4089

Radiation pressure is the force exerted on an object by electromagnetic radiation. It is a real and measurable force, although it is usually very s...

Radiation
4090

Radiation is the emission or transmission of energy in the form of waves or particles. It can be classified into two types: ionizing and non-ionizing.

Radioactivity
4091

Radioactivity is the process by which unstable atoms lose energy by emitting radiation in the form of particles or electromagnetic waves. This proc...

Faraday Constant
4092

The Faraday constant, denoted by the symbol F, is a fundamental physical constant that relates the charge of one mole of electrons to the amount of...

Radius Of Gyration
4092

The radius of gyration is a measure of the distribution of mass within an object. It is defined as the distance from the object's center of mass to...

Ferromagnetism
4093

Ferromagnetic materials are a class of materials that exhibit strong magnetic properties due to the alignment of their atomic magnetic moments. The...

Raman Scattering
4093

Raman scattering is a spectroscopic technique used to study vibrational, rotational, and other low-frequency modes in a system. It is based on the ...

Rare Earth Magnets
4094

Rare earth magnets are a class of permanent magnets made from alloys of rare earth elements. They are the most powerful type of permanent magnet, a...

Force Between Multiple Charges
4095

The magnitude of the electrostatic force between two point charges is given by Coulomb's law:

Force
4096

Force is a physical quantity that describes an interaction that can change the motion of an object. It is measured in newtons (N) in the Internatio...

Reactance And Impedance
4096

Reactance and impedance are two important concepts in electrical engineering. They are used to describe the behavior of electrical circuits when al...

Rectifier
4097

A rectifier is an electrical device that converts alternating current (AC) into direct current (DC). The process of converting AC to DC is known as...

Friction
4098

Friction is the force that opposes the relative motion of two objects in contact. It is a fundamental force in nature that affects everything from ...

Frictional Force
4099

Frictional force is the force that opposes the relative motion of two objects in contact. It is a non-conservative force, meaning that the work don...

Galilean Transformation
4100

The Galilean transformation is a mathematical transformation that describes the relationship between the coordinates of an object in two different ...

Refractive Index
4100

The refractive index of a material is a measure of how much light bends when passing through it. It is defined as the ratio of the speed of light i...

Gauge
4101

A gauge is a type of meter that measures the magnitude of a physical quantity. Gauges are used in a wide variety of applications, including measuri...

Refrigeration
4101

Refrigeration is the process of removing heat from a substance or space, resulting in a lower temperature. It is used in a wide range of applicatio...

Geiger Counter
4102

A Geiger counter is a device used to detect and measure ionizing radiation, such as gamma rays and X-rays. It is named after the German physicist H...

Relation Between Amplitude And Frequency
4102

In physics, amplitude and frequency are two fundamental properties of a periodic wave. Amplitude refers to the maximum displacement of a wave from ...

Relation Between Bar And Atm
4103

Pressure is a physical quantity that measures the force applied perpendicular to the surface of an object per unit area. It is a scalar quantity, m...

Hall Effect
4104

The Hall effect is the production of a voltage difference (the Hall voltage) across a conductor, usually a metal, when it is subjected to a magneti...

Relation Between Beta And Gamma Function
4104

The Beta function and the Gamma function are two closely related special functions that play a fundamental role in various areas of mathematics, st...

Halleys Comet
4105

Halley's Comet is a bright comet that orbits the Sun every 75 to 76 years. It is one of the most famous comets in history and has been observed by ...

Relation Between Critical Angle And Refractive Index
4105

The critical angle, also known as the limiting angle, is a crucial concept in the field of optics, particularly in the study of light refraction an...

Harmonic Oscillator
4106

A harmonic oscillator is a system that, when displaced from its equilibrium position, experiences a restoring force proportional to the displacemen...

Relation Between Escape Velocity And Orbital Velocity
4107

Escape velocity is the minimum speed an object needs to escape the gravitational pull of a massive body, such as a planet or moon. Once an object r...

Relation Between Kp And Kc
4108

In chemistry, $Kp$ refers to the equilibrium constant for a chemical reaction expressed in terms of partial pressures of the gaseous reactants and ...

Relation Between Newton And Dyne
4109

English mathematician and physicist who is widely credited as one of the most influential scientists of all time.

Humidity
4110

Humidity refers to the amount of water vapor present in the air. It is an essential component of the Earth's atmosphere and plays a crucial role in...

Relation Between Pressure And Density
4110

Pressure and density are two fundamental properties of matter that are closely related. Pressure is the force per unit area exerted by a substance,...

Huygens Principle
4111

Huygens' principle is a method for understanding how waves propagate. It was developed by the Dutch scientist Christiaan Huygens in the 17th centur...

Relation Between Youngs Modulus And Bulk Modulus
4111

Young's modulus, also known as the modulus of elasticity, is a measure of the stiffness of a material. It is defined as the ratio of the stress (fo...

Relative Humidity
4112

Relative humidity (RH) is a measure of the amount of water vapor present in the air compared to the maximum amount of water vapor the air can hold ...

Hydrostatic Pressure
4113

Hydrostatic pressure is the pressure exerted by a fluid at rest due to the force of gravity. It is a scalar quantity and is measured in pascals (Pa...

Resistivity
4113

Resistivity is a measure of how strongly a material opposes the flow of electric current. It is defined as the electrical resistance of a material ...

Hysteresis
4114

A hysteresis loop is a graphical representation of the relationship between the magnetic field strength (H) and the magnetization (M) of a material...

Resistor
4114

A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resis...

Infrared Radiation
4115

Infrared radiation (IR) is a type of electromagnetic radiation that is invisible to the human eye. It is located on the electromagnetic spectrum be...

Resolving Power
4115

Resolving power is the ability of an optical instrument to distinguish between two closely spaced objects. It is usually measured in terms of the m...

Integrated Circuit
4116

An integrated circuit (IC), also known as a chip or microchip, is a small electronic circuit made of semiconductor material that has been fabricate...

Resonance
4116

Resonance is a phenomenon that occurs when a system is subjected to a periodic force that matches its natural frequency of vibration. This causes t...

Reverberation
4117

Reverberation is the persistence of sound in a space after the sound source has stopped. It is caused by the reflection of sound waves off surfaces...

International Space Station
4118

The International Space Station (ISS) is a modular space station in low Earth orbit. It is a joint project of five participating space agencies: NA...

Rheostat
4118

A rheostat is a variable resistor used to control the flow of electric current. It consists of a resistive element, usually a wire, and a sliding c...

Ionizing Radiation
4119

Ionizing radiation is a type of high-energy radiation that has enough energy to remove tightly bound electrons from atoms, resulting in the formati...

Satellite Communication
4119

Satellite communication is a type of wireless communication that uses satellites to relay signals between two or more points on Earth. It is used f...

Isothermal Process
4120

An isothermal process is a thermodynamic process in which the temperature of the system remains constant. This means that the internal energy of th...

Scintillation Counter
4120

A scintillation counter is a device used to detect and measure ionizing radiation. It consists of a scintillator, a photomultiplier tube (PMT), and...

James Webb Space Telescope
4121

The James Webb Space Telescope (JWST) is a space telescope under construction and development by NASA, the European Space Agency (ESA) and the Cana...

Seebeck Effect
4121

The Seebeck effect is the conversion of temperature differences directly into electrical energy. It is named after the German physicist Thomas Joha...

Junction Field Effect Transistor
4122

A Junction Field-Effect Transistor (JFET) is a type of field-effect transistor that uses a semiconductor junction to control the flow of current. J...

Seismograph
4122

A seismograph is a device that records the motion of the ground during an earthquake. The first seismographs were invented in China in the 2nd cent...

Junction Transistor
4123

A junction transistor is a semiconductor device that acts as an electronic switch or an amplifier. It is made of three layers of semiconductor mate...

Sharpness Of Resonance
4123

Resonance is a phenomenon that occurs when a system is subjected to a periodic force whose frequency is equal to or close to the system's natural f...

Shear Stress
4124

Shear stress is the force per unit area that acts parallel to the surface of a material and causes it to deform. It is expressed in units of pascal...

Kinetic Friction
4125

Kinetic friction is the force that opposes the motion of an object when it is in contact with another surface and moving relative to that surface. ...

Lambert Cosine Law
4126

Lambert's Cosine Law, also known as the cosine emission law, describes the relationship between the intensity of light emitted by a surface and the...

Sliding Friction
4126

Sliding friction is the force that opposes the relative motion of two solid surfaces in contact. It is a type of kinetic friction, which is the for...

Laplace Correction
4127

Laplace correction is a technique used in probability theory and statistics to adjust the probabilities of events in order to account for the fact ...

Solar Eclipse
4127

A solar eclipse occurs when the Moon passes between the Sun and Earth, and the Moon's shadow falls on Earth's surface. Solar eclipses are rare even...

Laser Diode
4128

A laser diode is a semiconductor device that emits coherent light when an electric current is passed through it. Laser diodes are used in a wide va...

Solenoid Engine
4128

A solenoid is an electromechanical device that converts electrical energy into mechanical energy. It consists of a coil of wire wrapped around a me...

Laser
4129

A laser is a device that emits light through a process called stimulated emission. The term "laser" originated as an acronym for "light amplification by stimulated emission of radiation".

Solenoid
4129

A solenoid is an electromechanical device that converts electrical energy into mechanical energy. It consists of a coil of wire wrapped around a me...

Millikan Oil Drop Experiment
4130

The Millikan oil drop experiment was a series of experiments conducted by Robert Millikan and Harvey Fletcher between 1909 and 1913. The experiment...

Solid State Physics
4130

Solid-state physics is the study of the physical properties of solids, including their electronic structure, thermal properties, mechanical propert...

Sonication
4131

Sonification is the process of converting data into sound. This can be done for a variety of purposes, such as:

Moon
4132

The Moon is the fifth largest moon in the Solar System and the largest in our own. It is a natural satellite of Earth, orbiting it at an average di...

Sonometer
4132

A sonometer is a scientific instrument used to measure the frequency of sound waves. It consists of a stretched string, a fixed pulley, a movable p...

Motion In A Plane
4133

Motion in a plane is the movement of an object in two dimensions. It can be described by the object's position, velocity, and acceleration.

Murphys Law
4134

Murphy's Law is a popular adage that states that "anything that can go wrong, will go wrong." It is often used to describe the unexpected and often pessimistic nature of real-world situations.

Navier Stokes Equation
4135

The Navier-Stokes equations are a set of partial differential equations that describe the motion of viscous fluids. They are named after the French...

Special Theory Of Relativity
4135

The Special Theory of Relativity, proposed by Albert Einstein in 1905, is a fundamental theory in physics that describes the relationship between s...

Specific Gravity
4136

Specific gravity is a measure of the density of a substance relative to the density of water. It is defined as the ratio of the density of a substa...

Newtons Law Of Viscosity
4137

Viscosity is a property of fluids that describes their resistance to flow. It is caused by the interaction of the molecules in the fluid, which col...

Newtons Second Law Of Motion
4138

Newton's Second Law of Motion is a fundamental principle in classical mechanics that describes the relationship between an object's mass, accelerat...

Speed And Velocity
4138

Speed is a measure of how fast an object is moving. It is calculated by dividing the distance traveled by the time taken to travel that distance. S...

Newton's Third Law Of Motion
4139

Complete guide to Newton's third law including action-reaction pairs, applications, examples, rocket propulsion for NEET physics

Normal Force
4140

In physics, the normal force is the force exerted by a surface on an object in contact with it, perpendicular to the surface. It is also known as t...

Nuclear Force
4141

Nuclear force is the force that holds protons and neutrons together inside an atomic nucleus. It is one of the four fundamental forces in nature, a...

Optical Bench
4143

An optical bench is a stable platform used to hold and align optical components, such as lenses, mirrors, and prisms, in a precise and repeatable m...

Paramagnetism
4144

Paramagnetism is a form of magnetism that occurs when certain materials are exposed to an external magnetic field. These materials, known as parama...

Pendulum
4145

A pendulum is a weight suspended from a pivot so that it can swing freely. When the pendulum is displaced from its equilibrium position, it will os...

Periscope
4146

Periscope is a live video streaming app that allows users to broadcast live video to their followers. It was launched in 2015 and was acquired by T...

Angular Momentum Of Electron
4152

In quantum mechanics, the angular momentum of an electron is a fundamental property that describes the electron's rotational motion. It is a vector...

Angular Velocity
4153

Angular velocity is a measure of how fast an object is rotating. It is defined as the rate of change of the angular displacement of an object with ...

Antimatter
4154

Antimatter is a type of matter that is composed of antiparticles, which are the opposite of their corresponding particles. For example, the antipar...

Average Speed
4155

Average speed is the total distance traveled divided by the total time taken to travel that distance. It is a measure of how fast an object is movi...

Avogadro Hypothesis
4156

Avogadro's Hypothesis states that under the same conditions of temperature and pressure, equal volumes of gases contain an equal number of molecule...

Balanced Force
4157

A balanced force occurs when the net force acting on an object is zero. This means that the forces acting on the object are equal in magnitude and ...

Ballistics
4158

Ballistics is the science of the motion of projectiles. It is a branch of physics that deals with the behavior of projectiles in flight, including ...

Band Theory Of Solids
4159

The band theory of solids is a fundamental concept in solid-state physics that describes the electronic structure of materials. It provides a frame...

Bar Magnet As An Equivalent Solenoid
4160

A bar magnet can be considered as an equivalent solenoid, which is a coil of wire that carries an electric current and creates a magnetic field. Th...

Barometer
4161

A barometer is a scientific instrument used to measure atmospheric pressure. It is a device that measures the weight of the air above a given point...

Bells Theorem
4162

Bell's theorem is a no-go theorem in quantum mechanics that states that no physical theory can reproduce all the predictions of quantum mechanics w...

Bernoullis Principle
4163

Bernoulli's principle is a fundamental principle in fluid dynamics that describes the relationship between fluid velocity, pressure, and height. It...

Bipolar Junction Transistor
4164

A bipolar junction transistor (BJT) is a three-terminal electronic device that acts as an amplifier or switch. It is made of semiconductor material...

Black Body Radiation
4165

Black body radiation refers to the electromagnetic radiation emitted by an ideal black body. A black body is a theoretical concept that absorbs all...

Boltzmann Constant
4166

The Boltzmann constant, denoted by the symbol $kB$, is a fundamental physical constant that relates the average kinetic energy of particles in a sy...

Braille
4167

Braille is a tactile writing and reading system used by blind and visually impaired people. It was invented by Louis Braille, a blind Frenchman, in...

Buoyant Force
4168

Buoyant force is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In other words, it is the upwa...

Calorimeter
4169

A calorimeter is a device used to measure the heat involved in a chemical reaction or physical change. It is typically made of metal and is insulat...

Centre Of Mass And Centre Of Gravity
4170

The centre of mass of an object is the point where all of its mass is evenly distributed. It is also known as the centroid or the geometric centre.

Centripetal Force
4171

Centripetal force is the net force that acts on an object moving in a circular path, pulling it toward the center of the circle. It is directed tow...

Charge Transfer
4173

Charge transfer is the movement of electrons from one atom or molecule to another. It is a fundamental process in chemistry and biology, and it pla...

Charging By Induction
4174

Induction charging is a method of wirelessly transferring electrical energy between two objects. It is based on the principle of electromagnetic in...

Cherenkov Radiation
4175

Cherenkov radiation is a unique and fascinating optical phenomenon that occurs when a charged particle moves through a medium at a speed greater th...

Circuit Breakers
4176

A circuit breaker is a protective device that automatically switches off an electrical circuit when the current exceeds a safe level. This prevents...

Circuit Components
4177

An electric circuit is a path that allows electricity to flow. It consists of a source of electrical energy, such as a battery, and a load, such as...

Clausius Statement
4178

The Clausius statement of the second law of thermodynamics is one of the fundamental principles of thermodynamics. It states that heat cannot spont...

Coherent Sources
4179

In physics, a coherent source is a source of waves that have a constant phase relationship with each other. This means that the waves from a cohere...

Collision
4180

Collisions occur when two or more objects come into contact with each other. There are different types of collisions, each with its own characteris...

Commutator
4181

A commutator is a mechanical device used in direct current (DC) motors and generators to reverse the direction of current flow in the armature wind...

Compound Microscope
4182

A compound microscope is a type of microscope that uses two or more lenses to produce a magnified image of a specimen. The objective lens, which is...

Concave Lens
4184

A concave lens, also known as a diverging lens, is a type of lens that causes light rays to diverge (spread out) after passing through it. Unlike a...

Conductor And Insulator
4185

Conductors and insulators are two important concepts in the field of electricity. Conductors are materials that allow electricity to flow through t...

Conservative Force
4187

A conservative force is a force that does work on an object that depends only on the initial and final positions of the object and not on the path ...

Constellations
4188

A constellation is a group of stars that form a recognizable pattern in the night sky. Constellations have been used for centuries by astronomers t...

Convex Mirror
4189

A convex mirror is a curved mirror with a reflecting surface that bulges outward. It is also known as a diverging mirror because it causes light ra...

Cyclic Process
4191

A cyclic process is a process that repeats itself over and over again. It is a closed loop, with no beginning or end. Cyclic processes are found in...

Cyclotron
4192

A cyclotron is a type of particle accelerator that uses a strong magnetic field to accelerate charged particles in a circular path. It was invented...

Davisson Germer Experiment
4193

The Davisson-Germer experiment was a landmark experiment in physics that demonstrated the wave-particle duality of matter. It was conducted by Clin...

DC Generator
4194

A DC generator is an electrical machine that converts mechanical energy into direct current (DC) electrical energy. It is based on the principle of...

Decibel
4195

A decibel (dB) is a unit of measurement used to express the relative intensity of a sound. It is a logarithmic unit, which means that it expresses ...

Delta Modulation
4196

Delta modulation (DM) is a simple form of analog-to-digital conversion (ADC) that uses a one-bit quantizer to represent the difference between the ...

Derivation Of Equation Of Motion
4197

The equation of motion is a fundamental concept in physics that describes the behavior of objects in motion. It provides a mathematical framework t...

Derivation Of Lorentz Transformation
4198

The Lorentz transformation is a mathematical transformation that describes how space and time are related in special relativity. It was developed b...

Derivation Of Potential Energy
4199

Complete guide to potential energy derivation including gravitational potential energy, elastic potential energy, chemical potential energy, formula for NEET physics

Derivation Of Prism Formula
4200

The prism formula is an equation that describes the angle of deviation of a light ray passing through a prism. It is given by:

Deuterium
4201

Deuterium is a naturally occurring isotope of hydrogen with a nucleus containing one proton and one neutron, making it twice as heavy as the most c...

Diamagnetism
4202

Diamagnetism is a form of magnetism that occurs in all materials, but it is usually very weak. It is caused by the orbital motion of electrons in r...

Difference Between Centre Of Gravity And Centroid
4206

The centre of gravity (CG), also known as the centre of mass, is the point where all the mass of an object is considered to be concentrated. It is ...

Difference Between Echo And Reverberation
4207

Sound waves are mechanical waves that travel through a medium, such as air, water, or solids. They are caused by the vibration of particles in the ...

Difference Between Emission And Absorption Spectra
4208

Atomic spectra are the characteristic patterns of electromagnetic radiation emitted or absorbed by atoms. They are caused by the transitions of ele...

Difference Between Kinetics And Kinematics
4210

Kinetics is the branch of physical chemistry that deals with the rates of chemical reactions. It is a fundamental science that has applications in ...

Difference Between Mirror And Lens
4211

A mirror is a reflective surface, usually made of glass with a metallic coating, that reflects light and images. Mirrors are used to see reflection...

Difference Between Real Image And Virtual Image
4212

A real image is an image that is formed by the convergence of light rays. It can be projected onto a surface, such as a screen or a wall. Real imag...

Difference Between RTD And Thermocouple
4213

RTD stands for Resistance Temperature Detector. It is a temperature sensor that uses the principle of resistance change with temperature to measure...

Difference Between Simple And Compound Microscope
4214

A simple microscope, also known as a magnifying glass, is a basic optical instrument that produces magnified images of small objects. It consists o...

Difference Between Solar Eclipse And Lunar Eclipse
4215

A solar eclipse occurs when the Moon passes between the Sun and Earth, and the Moon's shadow falls on Earth. This can only happen during a new moon...

Differences Between Acceleration And Velocity
4217

In physics, motion is a fundamental concept that describes the change in position of an object over time. Two key concepts related to motion are ve...

Differences Between Enthalpy And Entropy
4218

Enthalpy is a thermodynamic property that measures the total energy of a system, including its internal energy and the energy associated with its p...

Diode As A Rectifier
4219

A diode is a two-terminal electronic component that allows current to flow in only one direction. This property makes diodes useful for a variety o...

Magnet
4368

A magnet is a material or object that produces a magnetic field. This magnetic field is invisible, but it can be detected by its effects on other m...

Manometer
4374

A manometer is a device used to measure pressure in a fluid, typically a gas or liquid. It consists of a vertical tube with one end open to the atm...

Mass Of Deuteron
4375

A deuteron is a stable isotope of hydrogen with a nucleus containing one proton and one neutron, bound together by the strong nuclear force. It is ...

Mean Free Path
4376

The mean free path of a particle is the average distance it travels before undergoing a collision with another particle. It is an important concept...

Permanent Magnet
4377

A permanent magnet is a material or object that produces its own magnetic field without the need for an electric current. The magnetic field of a p...

Perpetual Motion
4378

Perpetual motion is the idea of a machine that can operate indefinitely without an external energy source. This concept has fascinated inventors an...

Photon
4380

A photon is an elementary particle that is the quantum of light and all other forms of electromagnetic radiation. It is the basic unit of light and...

Photovoltaic Cell
4381

A photovoltaic (PV) cell, also known as a solar cell, is a device that converts light energy into electrical energy. The process of converting ligh...

Pin Diode
4383

A PIN diode is a type of semiconductor diode that has a wide, intrinsic semiconductor region between its p-type and n-type regions. This intrinsic ...

Plane Mirror
4384

A plane mirror is a flat, reflective surface that produces an image of an object by reflecting light rays. It is also known as a flat mirror or a l...

PN Junction Diode
4385

A PN junction diode is a semiconductor device that allows current to flow in one direction only. It is made by joining two pieces of semiconductor ...

Poissons Ratio
4386

Poisson's ratio is a measure of a material's tendency to deform in one direction when subjected to stress in another direction. It is defined as th...

Spherometer
4387

A spherometer is a device used to measure the radius of curvature of a spherical surface. It consists of a metal base with a micrometer screw attac...

Sphygmomanometer
4388

A sphygmomanometer is a device used to measure blood pressure. It consists of an inflatable cuff wrapped around the upper arm, connected to a manom...

Stars
4390

A star is a luminous ball of gas, mostly hydrogen and helium, that produces its own light and heat through nuclear fusion reactions in its core. St...

Static Friction
4391

Static friction is the force that opposes the movement of two objects in contact with each other when they are not moving relative to each other. I...

Statistical Mechanics
4392

Statistical mechanics is a branch of physics that uses probability theory to describe the macroscopic properties of large systems of particles. It ...

String Theory
4393

String theory is a branch of theoretical physics that proposes that the point-like particles of particle physics are not actually points, but rathe...

Synchrotron
4395

A synchrotron is a type of particle accelerator that uses electromagnetic fields to propel charged particles to high speeds and energies. Synchrotr...

Tension Force
4396

Tension force is a pulling force that acts along the length of an object, tending to stretch or elongate it. It is not one of the four fundamental ...

Terminal Velocity
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Terminal velocity is the constant speed at which an object falls through a fluid (such as air or water) when the resistance of the fluid to the obj...

The International System Of Units
4398

The Seven Defining Constants are a set of fundamental physical constants that are used to describe the universe. They are:

Thermal Diffusivity
4399

Thermal diffusivity is a measure of how quickly heat flows through a material. It is defined as the ratio of the thermal conductivity to the heat c...

Thermal Expansion
4401

Thermal expansion is the phenomenon in which the dimensions of a solid object increase when its temperature is raised. This is due to the increased...

Thermal Stress
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Thermal stress is a type of mechanical stress that occurs due to a difference in temperature within a material or between two materials in contact....

Joule’s Law
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In 1840, a British scientist named James Prescott Joule found out that the heat generated in an electric circuit is directly related to the circuit...

Magnetic Lines Of Force
4988

Magnetic lines of force are a way of visualizing the magnetic field around a magnet. They are imaginary lines that show the direction and strength ...

Micrometer
4990

A micrometer, also known as a micrometer screw gauge or simply a micrometer, is a device used for precise measurement of small distances. It is a v...

Timbre
4991

Timbre is a perceptual attribute of sound that allows us to distinguish between different sounds, even when they have the same pitch and loudness. ...

Time Dilation Length Contraction Relative Speed
4992

Time dilation is a phenomenon in which time appears to pass more slowly for an observer in relative motion than for an observer at rest. This is a ...

Toric Lens
4993

A toric lens is a type of contact lens or intraocular lens (IOL) that corrects astigmatism, a condition in which the cornea or lens of the eye is n...

Torque On A Dipole
4994

Torque is a measure of the twisting force applied to an object. It is defined as the product of the force applied to an object and the perpendicula...

Total Internal Reflection
4995

Total internal reflection (TIR) is a phenomenon that occurs when light traveling in a denser medium strikes a boundary with a less dense medium at ...

Transducer
4996

A transducer is a device that converts one form of energy into another. Transducers are used in a wide variety of applications, including:

Transistor
4997

A transistor is a semiconductor device that acts as a switch or an amplifier. It is made of three layers of semiconductor material, with the middle...

Translatory Motion
4998

Translatory motion is a type of motion in which an object moves from one place to another without rotating about an axis. In other words, it is a m...

Translucent Materials
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Translucent materials are those that allow light to pass through them, but not in a clear and distinct way. They scatter light, making it difficult...

Types Of Battery
5002

Batteries are devices that store chemical energy and convert it into electrical energy. They are used in a wide variety of applications, from small...

Types Of Cables
5003

A cable is a flexible structure made of one or more strands of wire, rope, or other flexible material. Cables are used to transmit electrical power...

Types Of Connectors
5004

Connectors are devices or components that establish a connection between two or more systems, devices, or networks. They facilitate the exchange of...

Types Of DC Motors
5005

DC motors are classified into various types based on their construction, winding, and commutation methods. Each type has its unique characteristics...

Types Of Motion
5006

Motion is the change in the position of an object over time. There are different types of motion, each with its own characteristics.

Types Of Motors
5007

Motors are devices that convert electrical energy into mechanical energy. They are used in a wide variety of applications, from small appliances to...

Types Of Radiation
5008

Radiation is the emission or transmission of energy in the form of waves or particles. There are different types of radiation, each with its own ch...

Types Of Resistors
5009

Resistors are passive electronic components that impede the flow of electric current by introducing resistance. They are used in a wide range of el...

Types Of Switches
5010

Switches are devices used to control the flow of electricity in a circuit. They can be classified into various types based on their construction, o...

Uniform Circular Motion
5011

Uniform circular motion is the motion of an object moving at a constant speed along a circular path. The object's velocity is constantly changing d...

Unit Of Resistance
5012

A unit of resistance is a measure that impedes the flow of electric current. The most common type of unit of resistance is the ohm, which is a unit...

Units And Measurements
5013

In science, a unit is a standard quantity used to measure other quantities of the same kind. Units are essential for communication and comparison o...

Uses Of Optical Fibre
5014

Optical fibres are thin, flexible strands of glass or plastic that transmit light signals over long distances. They are used in a wide variety of a...

Uses Of Transformer
5015

Transformers are electrical devices that transfer electrical energy from one circuit to another through inductively coupled conductors—the transfor...

Uses Of Zener Diode
5016

A Zener diode is a type of semiconductor diode that exhibits a sharp increase in reverse voltage when it reaches a certain threshold voltage, known...

Variable Star
5017

A variable star is a star whose brightness varies over time. This variation in brightness can be caused by a number of factors, including:

Velocity Selector
5018

A velocity selector is a device that selects charged particles based on their velocity. It is used in various applications, such as mass spectromet...

Velocity Time Graphs
5019

A velocity-time graph is a graphical representation of the velocity of an object as a function of time. It is a useful tool for analyzing the motio...

Viscosity
5020

Viscosity is the property of a fluid that opposes the relative motion between its adjacent layers. It is a measure of the fluid's resistance to flo...

Voltmeter
5022

A voltmeter is an instrument used to measure the electrical potential difference between two points in a circuit. It is typically used to measure t...

Wave Motion
5024

Wave motion is simply how waves move. A wave is a disturbance that moves energy from one place to another. You can see wave motion in the ripples i...

Weather
5030

Weather refers to the short-term state of the atmosphere in a specific location. It is characterized by various elements such as temperature, humid...

Weightlessness
5031

Weightlessness is a condition in which an object appears to have no weight. This can occur when an object is in free fall, or when it is in orbit a...

Wiedemann Franz Law
5033

The Wiedemann Franz law states that the ratio of the thermal conductivity of a metal to its electrical conductivity is proportional to the temperat...

Work Done By Variable Force
5034

A variable force is a force whose magnitude changes as it acts on an object. The work done by a variable force is the integral of the force with re...

Yield Strength
5036

Yield strength is a material property that indicates the amount of stress required to cause permanent deformation in a material. It is an important...

Youngs Double Slit Experiment
5037

Interference is a phenomenon in which two or more waves combine to form a new wave pattern. In the case of light, interference can occur when two o...

Engineering Mechanics Equilibrium And Friction
15200

An equivalent force system is a system of forces that produces the same effect on a rigid body as a given force system. In other words, the two for...

Difference Between Resistance And Resistivity
15245

Resistance and resistivity are two fundamental concepts in the field of electricity. While they are related, they are not the same thing. Resistanc...

Application And Uses Of Based Articles In Physics
16561786

Physics is a fundamental science that helps us understand how the universe behaves. It's a subject that can seem challenging, but its principles ha...

Constants In Physics
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Physical constants are quantities with fixed values that do not change, regardless of when or where they are measured. They are fundamental to our ...

Derivation Of Physics Formulas
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Physics is a subject that is fundamentally based on mathematical equations and their derivations. These derivations help us understand the underlyi...

Differences & Comparisons Articles In Physics
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Differences and comparisons articles in Physics are essential for several reasons. They provide a comprehensive understanding of various physical p...

Laws Of Physics
16561790

Physics is a branch of science that deals with the study of matter and its motion through space and time, along with related concepts such as energ...

List Of Physics Scientists And Their Inventions
16561791

1. Sir Isaac Newton (1643-1727): Newton is best known for his laws of motion and universal gravitation. He also made significant contributions to o...

Puzzles And Brain Teasers
16561793

Complete guide to physics puzzles including motion problems, energy puzzles, force problems, Newton's laws applications for NEET physics

Relation Between Based Articles In Physics
16561794

Understanding the relationship between energy and matter is fundamental to the field of physics and has numerous advantages. This relationship is f...

Types And Classifications Based Articles In Physics
16561796

The use of types and classification of articles in Physics is a crucial aspect of scientific literature. This approach offers several advantages th...

Value Of Constants In Physics
16561797

In physics, constants are fixed values that do not change. They are often fundamental characteristics of the universe, and they are used to describ...

Mechanics
16561802

Mechanics is a branch of physics that deals with the motion of objects and the forces that cause this motion. It is divided into two main sub-field...

Motion In Physics
16561803

Complete guide to motion in physics including types, linear motion, rotational motion, Newton's laws, velocity, acceleration for NEET physics

Relativity
16561805

Relativity is a fundamental concept in physics, proposed by Albert Einstein, which describes how the laws of physics apply equally in all non-accel...

Ampere'S Law
16561808

André-Marie Ampère was a French physicist and mathematician who made significant contributions to the field of electromagnetism. He is best known f...

Archimedes Principle
16561809

Archimedes' Principle states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is ...

Doppler Effect
16561811

The Doppler effect is a phenomenon that occurs when a source of sound or light is moving relative to an observer. It causes the frequency of the so...

Kirchhoff'S Law
16561813

Kirchhoff's Law, named after the German physicist Gustav Kirchhoff, consists of two fundamental principles that govern electrical circuits.

Laws Of Reflection
16561814

The Laws of Reflection describe the behavior of light when it interacts with a surface. They are:

Lenz'S Law
16561815

- Lenz's law is a fundamental principle in electromagnetism that describes the direction of the electromotive force (EMF) induced in a conductor wh...

Newton'S Laws Of Motion
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Complete guide to Newton's laws of motion including law of inertia, F=ma, action-reaction, applications, and examples for NEET physics

Ohm'S Law
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Ohm's Law is a fundamental principle in electrical engineering that describes the relationship between voltage, current, and resistance in an elect...

Unit Of Density
16561820

The unit of density is mass per unit volume. It is a measure of how much mass is packed into a given space. The most common unit of density is kilo...

Unit Of Force
16561822

Force is a physical quantity that describes an interaction that can change the motion of an object. The SI unit of force is the newton (N), named a...

Unit Of Power
16561825

A unit of power is a measure of the rate at which work is done or energy is transferred. The most common unit of power is the watt (W), named after...

Unit Of Pressure
16561826

Pressure is a physical quantity that measures the force applied perpendicular to a surface per unit area. Several units are used to measure pressur...

Unit Of Viscosity
16561827

The unit of viscosity is the poise (P), named after the French physician Jean Léonard Marie Poiseuille. It is defined as the dynamic viscosity of a...

Atmosphere
16561960

The term atmosphere refers to the layer of gases that surrounds a celestial body, such as a planet or moon. Here are some key points about the atmo...

Celestial Bodies
16561961

Celestial bodies are astronomical objects that exist in the universe beyond Earth's atmosphere. They include stars, planets, moons, asteroids, come...

Communication Systems
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Communication systems are the means by which information is transmitted from one point to another. They can be classified into two main types: anal...

Deformation Of Solids
16561964

Deformation of solids refers to the change in shape or size of a solid material under the influence of external forces. It occurs when the applied ...

Diodes
16561965

Diodes are semiconductor devices that allow current to flow in only one direction. They are essential components in many electronic circuits, such ...

Earth Science
16561966

Earth science is the study of the planet Earth and its systems. It encompasses various scientific disciplines that explore the physical, chemical, ...

Electromagnetism
16561971

Electromagnetism is a branch of physics that deals with the relationship between electricity and magnetism. It is based on the principle that elect...

Electrostatics
16561972

Electrostatics is the branch of physics that deals with the behavior of electric charges at rest. The basic law of electrostatics is Coulomb's law,...

Force
16561974

Complete guide to force including definition, types, Newton's laws, formula F=ma, gravitational force, friction, and applications for NEET physics

Friction
16561976

Complete guide to friction including types, static friction, sliding friction, rolling friction, factors affecting friction, applications for NEET physics

Fundamental And Derived Units Of Measurement
16561977

Fundamental units are the basic units of measurement defined by the International System of Units (SI). They include the meter (m) for length, kilo...

Gravitation Gravitational Force And Newton'S Law Of Gravitation
16561978

Complete guide to gravitation including gravitational force, Newton's law, Kepler's laws, universal gravitation, applications for NEET physics

Introduction To Motion
16561980

Motion is the change in position of an object over time. It can be described in terms of speed, velocity, and acceleration.

Kinetic Theory Of Gases
16561981

The Kinetic Theory of Gases is a fundamental concept in physics that describes the behavior of gases at the molecular level. According to this theo...

Radioactivity: Alpha Decay
16561987

Alpha decay is a type of radioactive decay in which an unstable atomic nucleus loses two protons and two neutrons, emitting an alpha particle. Alph...

Rotational Motion
16561988

Rotational motion occurs when an object spins or revolves around a fixed point or axis. It involves the motion of an object around its own axis wit...

Scalar And Vector
16561989

In physics, a scalar quantity is a quantity that is fully described by its magnitude, or size. Examples of scalar quantities include mass, temperat...

Scientific Methods
16561990

The scientific method is a systematic approach to the study of natural phenomena. It involves making observations, forming hypotheses, conducting e...

The Concept Of Pressure
16561994

Complete guide to pressure including definition, formula, atmospheric pressure, fluid pressure, applications, and units for NEET physics

Thermal Properties Of Materials
16561995

Thermal properties of materials describe how a material responds to changes in temperature. These properties are crucial in various engineering app...

Work, Energy And Power
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Complete guide to work, energy, and power including definitions, formulas, kinetic energy, potential energy, conservation of energy for NEET physics

SI Units in Physics
What is the SI Unit?

The SI unit, also known as the International System of Units, is the modern form of the metric system and is the most widely used system of measurement in the world. It is an international standard for physical measurements and is used in all fields of science, as well as in everyday life.

The SI system is based on seven fundamental units, each of which is defined in terms of a specific physical quantity. These are:

  1. The meter (m) for length
  2. The kilogram (kg) for mass
  3. The second (s) for time
  4. The ampere (A) for electric current
  5. The kelvin (K) for thermodynamic temperature
  6. The mole (mol) for amount of substance
  7. The candela (cd) for luminous intensity

Each of these units is defined in a way that is reproducible and can be measured with great accuracy. For example, the meter is defined as the distance light travels in a vacuum in 1/299,792,458 of a second.

In addition to these seven base units, the SI system also includes a number of derived units, which are formed by combining the base units according to the rules of algebra. For example, the unit of force, the newton (N), is defined as a kilogram meter per second squared (kg·m/s²).

The SI system also includes a set of prefixes that can be added to any unit to create a multiple or fraction of that unit. For example, the prefix kilo- (k) means 1000, so a kilometer is 1000 meters.

The SI system is maintained and updated by the International Bureau of Weights and Measures (BIPM), which is based in France. The BIPM works with international partners to ensure that the SI units remain accurate and consistent across the world.

What is SI Units List?

The International System of Units, abbreviated as SI from the French “Système international d’unités,” is the modern form of the metric system and is the most widely used system of measurement. It comprises a coherent system of units of measurement built on seven base units. Each of these units is defined by a specific physical quantity that can be measured.

Here is a list of the seven base SI units:

  1. Meter (m): The meter is the SI unit for length. It is defined as the distance light travels in a vacuum in 1/299,792,458 of a second.

  2. Kilogram (kg): The kilogram is the SI unit for mass. It is defined by the Planck constant as exactly 6.62607015×10^-34 joule-second.

  3. Second (s): The second is the SI unit for time. It is defined by the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom.

  4. Ampere (A): The ampere is the SI unit for electric current. It is defined by taking the fixed numerical value of the elementary charge e to be 1.602176634×10^-19 when expressed in the unit C, which is equal to A.s.

  5. Kelvin (K): The Kelvin is the SI unit for thermodynamic temperature. It is defined by taking the fixed numerical value of the Boltzmann constant k to be 1.380649×10^-23 when expressed in the unit J.K^-1.

  6. Mole (mol): The mole is the SI unit for amount of substance. It is defined by specifying the number of particles in a substance, where one mole contains exactly 6.02214076×10^23 elementary entities.

  7. Candela (cd): The candela is the SI unit for luminous intensity. It is defined by taking the fixed numerical value of the luminous efficacy of monochromatic radiation of frequency 540×10^12 Hz, Kcd, to be 683 when expressed in the unit lm W^-1.

These seven base units are used in combination to derive additional units of measure. For example, the unit of force (newton, N) is derived from the base units of mass (kg), length (m), and time (s) using the equation N = kg*m/s^2. Similarly, the unit of pressure (pascal, Pa) is derived as Pa = N/m^2.

The SI system also includes a set of prefixes that indicate multiplication or division by a power of ten. For example, the prefix kilo- (k) indicates multiplication by 10^3, so a kilometer (km) is 10^3 meters. Conversely, the prefix milli- (m) indicates division by 10^3, so a millimeter (mm) is 10^-3 meters.

SI Base Units

The International System of Units, abbreviated as SI from the French “Système international,” is the modern form of the metric system and is the most widely used system of measurement. It comprises a coherent system of units of measurement built on seven base units. These base units are defined in terms of constants that are observed in the natural world.

  1. Meter (m): The meter is the SI base unit of length. It is currently defined as the length of the path traveled by light in a vacuum during a time interval of 1/299,792,458 of a second.

  2. Kilogram (kg): The kilogram is the SI base unit of mass. It was originally defined as the mass of one liter of water at its freezing point in 1794, but was redefined in 2019 in terms of the Planck constant (6.62607015×10^-34 m² kg / s).

  3. Second (s): The second is the SI base unit of time. It is currently defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom.

  4. Ampere (A): The ampere is the SI base unit of electric current. It is defined by taking the fixed numerical value of the elementary charge e to be 1.602176634×10^-19 when expressed in the unit C, which is equal to A.s.

  5. Kelvin (K): The kelvin is the SI base unit of thermodynamic temperature. It is defined by taking the fixed numerical value of the Boltzmann constant k to be 1.380649×10^-23 when expressed in the unit J/K.

  6. Mole (mol): The mole is the SI base unit of amount of substance. One mole contains exactly 6.02214076×10^23 elementary entities. This number is the fixed numerical value of the Avogadro constant, NA, when expressed in the unit mol^-1.

  7. Candela (cd): The candela is the SI base unit of luminous intensity. It is defined by taking the fixed numerical value of the luminous efficacy of monochromatic radiation of frequency 540×10^12 Hz, Kcd, to be 683 when expressed in the unit lm W^-1.

These seven base units are used in combination to derive all other units of measurement, including derived units like the newton (for force) and the joule (for energy).

SI Base Units List

The International System of Units (SI) is a globally accepted and used system of measurement. It is based on seven base units that define the 22 derived units with special names and symbols. The SI base units represent the seven fundamental quantities of nature.

  1. Meter (m): The meter is the SI base unit for length. It is defined as the distance traveled by light in a vacuum in 1/299,792,458 of a second.

  2. Kilogram (kg): The kilogram is the SI base unit for mass. It was originally defined as the mass of one liter of water at its freezing point. However, since 2019, it has been defined in terms of the Planck constant.

  3. Second (s): The second is the SI base unit for time. It is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom.

  4. Ampere (A): The ampere is the SI base unit for electric current. It is defined as the constant current which, if maintained in two straight parallel conductors of infinite length and negligible circular cross-section, and placed one meter apart in a vacuum, would produce a force between these conductors of 2 x 10^-7 newtons per meter of length.

  5. Kelvin (K): The Kelvin is the SI base unit for thermodynamic temperature. It is defined by setting the Boltzmann constant to 1.380649×10^-23 joules per kelvin.

  6. Mole (mol): The mole is the SI base unit for the amount of substance. It is defined as exactly 6.02214076×10^23 elementary entities. This number is the Avogadro constant.

  7. Candela (cd): The candela is the SI base unit for luminous intensity. It is defined as the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540×10^12 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian.

These seven base units are used in combination to measure other physical quantities. For example, speed is measured in meters per second (m/s), which is derived from the base units of meters and seconds.

SI Derived Units

SI derived units are units of measurement that are derived from the seven base units specified by the International System of Units (SI). These base units are the meter (m) for length, kilogram (kg) for mass, second (s) for time, ampere (A) for electric current, kelvin (K) for thermodynamic temperature, mole (mol) for amount of substance, and candela (cd) for luminous intensity.

SI derived units are formed by combining the base units, using the algebraic relations of the quantities they express. For example, the SI derived unit of force is the newton (N), which is defined as the force required to accelerate a one-kilogram mass by one meter per second squared (1 N = 1 kg·m/s²).

There are two types of SI derived units: those with a special name and symbol, and those without.

  1. SI derived units with special names and symbols: These include units like the newton (N) for force, pascal (Pa) for pressure, joule (J) for energy, watt (W) for power, coulomb (C) for electric charge, volt (V) for electric potential difference, ohm (Ω) for electric resistance, and many others. These units are used in various fields of science and engineering.

  2. SI derived units without special names and symbols: These are simply combinations of the base units or other derived units. For example, the SI derived unit for momentum is kilogram meter per second (kg·m/s), and the unit for density is kilogram per cubic meter (kg/m³).

SI derived units are coherent, which means they are defined in terms of the base units without any additional factors. This makes them easy to use and understand, and ensures consistency in their application across different fields of science and engineering. They are an essential part of the SI, the most widely used system of measurement in the world.

SI Derived Units List

The International System of Units (SI) is a globally accepted and widely used system of measurement. It consists of seven base units, namely: meter (m), kilogram (kg), second (s), ampere (A), kelvin (K), mole (mol), and candela (cd). These base units are used to derive other units of measurement that are used in various scientific and everyday contexts.

Here are some of the SI derived units:

  1. Hertz (Hz): This is the unit of frequency, defined as one cycle per second. It is derived from the base unit of time, the second.

  2. Newton (N): This is the unit of force. It is defined as the force required to accelerate a one-kilogram mass by one meter per second squared. It is derived from the base units of mass (kg), length (m), and time (s).

  3. Pascal (Pa): This is the unit of pressure. It is defined as one newton per square meter. It is derived from the base units of mass (kg), length (m), and time (s).

  4. Joule (J): This is the unit of energy. It is defined as the energy transferred when a force of one newton moves an object one meter. It is derived from the base units of mass (kg), length (m), and time (s).

  5. Watt (W): This is the unit of power. It is defined as one joule per second. It is derived from the base units of mass (kg), length (m), and time (s).

  6. Coulomb (C): This is the unit of electric charge. It is defined as the charge transported by a constant current of one ampere in one second. It is derived from the base unit of electric current (A) and time (s).

  7. Volt (V): This is the unit of electric potential and electromotive force. It is defined as one joule per coulomb. It is derived from the base units of mass (kg), length (m), time (s), and electric current (A).

  8. Ohm (Ω): This is the unit of electrical resistance. It is defined as one volt per ampere. It is derived from the base units of mass (kg), length (m), time (s), and electric current (A).

  9. Tesla (T): This is the unit of magnetic flux density. It is defined as one weber per square meter. It is derived from the base units of mass (kg), time (s), and electric current (A).

  10. Lumen (lm): This is the unit of luminous flux. It is defined as one candela steradian. It is derived from the base unit of luminous intensity (cd).

These are just a few examples of SI derived units. Each of these units has a specific definition and is used in specific contexts in science and engineering.

Advantages of Learning SI Units and CGS Units

The International System of Units (SI Units) and the Centimetre-Gram-Second (CGS) system of units are two of the most commonly used systems of measurement in the field of physics. Understanding and learning these units is crucial for several reasons.

  1. Universality: SI Units are universally accepted and used in scientific communities around the world. This makes communication and understanding of scientific concepts easier across different countries and cultures. For example, a meter in the United States is the same as a meter in China or France.

  2. Precision: Both SI and CGS units allow for precise measurements. This is particularly important in scientific experiments where even a small error in measurement can lead to significant errors in results and conclusions.

  3. Consistency: The SI system is based on seven fundamental units from which all other units are derived. This provides a consistent framework for all measurements. Similarly, the CGS system, though less commonly used now, provides a consistent framework based on the centimeter, gram, and second.

  4. Conversion Ease: Understanding both SI and CGS units allows for easy conversion between the two systems. This is particularly useful in fields where both systems are used. For example, in electromagnetism, some quantities are often measured in CGS units, while others are measured in SI units.

  5. Basis for Further Learning: A solid understanding of SI and CGS units provides a strong foundation for further learning in physics and other scientific disciplines. Many complex concepts in physics are easier to understand and apply if one has a good grasp of the basic units of measurement.

  6. Practical Applications: Both SI and CGS units have practical applications in everyday life. For example, understanding meters and kilograms (SI units) can help in estimating distances and weights, while understanding centimeters and grams (CGS units) can be useful in tasks like cooking or sewing.

In conclusion, learning SI Units and CGS Units is advantageous for anyone studying or working in a field that involves physical measurements. It aids in global scientific communication, ensures precision and consistency, facilitates conversion between systems, provides a basis for further learning, and has practical everyday applications.

Check the units of based articles in Physics given below.

In physics, units are a fundamental aspect of understanding and interpreting the physical world. They provide a standard for measuring and describing physical quantities, such as length, time, mass, and electric current. The International System of Units (SI) is the most widely used system of measurement in the world, and it is based on seven base units: the meter (m) for length, the kilogram (kg) for mass, the second (s) for time, the ampere (A) for electric current, the kelvin (K) for temperature, the mole (mol) for amount of substance, and the candela (cd) for luminous intensity.

When checking the units of based articles in physics, it’s important to ensure that the units used are consistent and appropriate for the physical quantities being measured or described. This involves checking that the units are correctly identified and used in calculations, and that they are consistent with the SI system or any other system of units being used.

For example, if an article is discussing the speed of light, it should use the unit meters per second (m/s), which is the SI unit for speed. If it’s discussing energy, it should use the unit joules (J), which is the SI unit for energy. If it’s discussing electric charge, it should use the unit coulombs (C), which is the SI unit for electric charge.

In addition, it’s important to check that the units are used consistently throughout the article. For example, if an article starts by using meters to measure length, it shouldn’t suddenly switch to using feet without explanation. Similarly, if an article is using the SI system, it shouldn’t suddenly switch to using the imperial system without explanation.

Finally, when checking the units of based articles in physics, it’s also important to check that the units are used correctly in calculations. This involves checking that the units are correctly converted when necessary, and that the units are correctly combined in calculations. For example, if an article is calculating speed by dividing distance by time, it should correctly convert the units of distance and time to meters and seconds, respectively, and the result should be in meters per second.

Frequently Asked Questions-FAQs
When were SI units established?

The International System of Units, known as SI units, was officially established and adopted during the 11th General Conference on Weights and Measures (CGPM) in 1960. However, the origins of the system can be traced back to the French Revolution.

During the late 18th century, the French Academy of Sciences was commissioned to design a new system of units that would be universal and could be used worldwide. This was in response to the chaos and confusion caused by the numerous units of measure that existed at the time. The result was the creation of the metric system, which was based on natural phenomena rather than arbitrary standards. For example, the meter was defined as one ten-millionth of the distance from the North Pole to the equator, and the kilogram was defined as the mass of one liter of water.

Over the years, the metric system evolved and was refined. In 1875, the Treaty of the Metre was signed, establishing the International Bureau of Weights and Measures (BIPM) to provide international control and coordination of the system.

In the 20th century, the need for even greater precision and consistency led to the development of the International System of Units. This system, which is based on the metric system, was designed to accommodate the needs of modern science and technology. It was officially adopted in 1960 at the 11th CGPM.

The SI system is based on seven base units: the meter (for length), the kilogram (for mass), the second (for time), the ampere (for electric current), the kelvin (for thermodynamic temperature), the mole (for amount of substance), and the candela (for luminous intensity). These units are defined in terms of constants of nature, such as the speed of light and the charge of the electron.

Since its establishment, the SI system has been periodically updated and revised to reflect advances in measurement science. The most recent major revision occurred in 2019, when the definitions of the kilogram, ampere, kelvin, and mole were updated.

Why is the SI system important?

The International System of Units, abbreviated as SI from the French “Système international d’unités,” is the modern form of the metric system and is the most widely used system of measurement. It is important for several reasons:

  1. Universal Standardization: The SI system provides a set of standard units that are used worldwide, which makes it easier for scientists, researchers, and students to understand, compare, and communicate data without confusion or misinterpretation. This is particularly important in fields like physics, chemistry, and engineering where precise measurements are crucial.

  2. Consistency and Accuracy: The SI system is based on seven fundamental units: the meter (for length), the kilogram (for mass), the second (for time), the ampere (for electric current), the kelvin (for temperature), the mole (for amount of substance), and the candela (for luminous intensity). These units are defined in a way that they can be accurately reproduced in laboratories around the world, ensuring consistency and accuracy in measurements.

  3. Scalability: The SI system uses decimal-based prefixes to scale these base units up and down, making it easy to express very large or very small quantities. For example, a kilometer is 1,000 meters, a millimeter is 0.001 meters, and a gigameter is 1,000,000,000 meters. This scalability makes the SI system flexible and adaptable to a wide range of applications.

  4. International Acceptance: The SI system is officially used in nearly every country in the world, with the notable exception of the United States, which still uses the Imperial system for many everyday measurements. However, even in the U.S., the SI system is used in scientific, academic, and many industrial settings.

  5. Ease of Conversion: Because the SI system is decimal-based, conversions within the system are straightforward and involve simply moving the decimal point. This is much simpler than conversions in systems like the U.S. customary units, where you have to remember things like 12 inches in a foot, 3 feet in a yard, and so on.

In summary, the SI system is important because it provides a universal, consistent, accurate, scalable, and easy-to-use system of measurement that is accepted and used around the world.

What are the common System of Units used in measurements?

In physics and everyday life, we use different systems of units to measure various quantities. The three most common systems of units are the International System of Units (SI), the British Imperial System, and the United States Customary Units.

  1. International System of Units (SI): This is the most widely used system of units in the world. It is a modern form of the metric system and is based on seven base units: the meter (m) for length, the kilogram (kg) for mass, the second (s) for time, the ampere (A) for electric current, the kelvin (K) for thermodynamic temperature, the mole (mol) for amount of substance, and the candela (cd) for luminous intensity. All other units are derived from these base units. The SI system is used in all scientific and most technical work.

  2. British Imperial System: This system of units, also known as the Imperial System, was used in the British Empire and is still used for some measures in the United Kingdom and other countries. It includes units such as the inch, foot, yard, and mile for length; the ounce and pound for weight; and the pint, quart, and gallon for volume. The Imperial System is not as coherent as the SI system, as it includes a number of different sub-systems with different base units.

  3. United States Customary Units: This system is used for most everyday measurements in the United States. It is similar to the British Imperial System but has some differences. For example, the US gallon is smaller than the UK gallon. The US Customary Units include the inch, foot, yard, and mile for length; the ounce and pound for weight; and the fluid ounce, cup, pint, quart, and gallon for volume.

Each of these systems has its own advantages and disadvantages. The SI system is the most widely used and is the easiest to use for scientific and technical calculations because it is a coherent system based on powers of ten. The British Imperial and US Customary systems are less coherent and can be more difficult to use for calculations, but they are still widely used in everyday life in some countries.

Define unit.

In physics, a unit is a standard measure of a quantity. It is a specific value of a physical quantity, defined and adopted by convention, with which other values of the same quantity can be compared to express their value. The definition, agreement, and practical use of units of measurement have played a crucial role in human endeavor from early ages up to the present. A multitude of systems of units used to be very common. Now there is a global standard, the International System of Units (SI), the modern form of the metric system.

For example, the unit of length in the International System of Units (SI) is the meter. This means that when we measure the length of an object, we compare it to the length of a meter and express the object’s length in terms of how many meters it is. Similarly, the unit of time in the SI system is the second. When we measure time, we compare it to the duration of a second and express the time in terms of how many seconds it is.

Units are crucial in physics and in science more generally because they allow us to quantify and compare physical quantities. Without units, we would not be able to say whether one object is longer, heavier, or hotter than another; nor would we be able to measure the speed of a car, the energy in a battery, or the force exerted by a machine.

In addition to the basic units of the SI system, there are also derived units, which are combinations of the basic units. For example, the unit of speed is meters per second, which is a combination of the basic units of length (meters) and time (seconds). The unit of force is the newton, which is a combination of the basic units of mass (kilograms), length (meters), and time (seconds).

Name the fundamental physical quantities.

Fundamental physical quantities, also known as base quantities, are the set of quantities in terms of which all other quantities can be expressed. They are independent and cannot be derived from each other. The International System of Units (SI) recognizes seven fundamental physical quantities. These are:

  1. Length: The measurement of how long or wide an object is. The SI unit is the meter (m).

  2. Mass: The measure of the amount of matter in an object. The SI unit is the kilogram (kg).

  3. Time: The ongoing sequence of events taking place. The SI unit is the second (s).

  4. Electric Current: The rate at which electric charge flows past a point in a circuit. The SI unit is the ampere (A).

  5. Thermodynamic Temperature: The measure of the average kinetic energy of the particles in a system. The SI unit is the kelvin (K).

  6. Amount of Substance: The measure of the number of elementary entities (atoms, molecules, ions, electrons, etc.) in a sample. The SI unit is the mole (mol).

  7. Luminous Intensity: The measure of the wavelength-weighted power emitted by a light source in a particular direction. The SI unit is the candela (cd).

These seven fundamental quantities are considered the building blocks of physical measurement. All other physical quantities, like velocity, force, power, etc., can be derived from these base quantities and are thus called derived quantities.