# Physics key terms

0.0 / 5

HideShow resource information

- Created by: xoxbeckywxox
- Created on: 05-04-17 14:21

acceleration

The rate of change of velocity, a vector quantity

1 of 230

Acceleration of free fall

The rate of change of velocity of an object falling in a gravitational field. Symbol g

2 of 230

Air Resistance

Drag or resistive force experienced by objects moving through air

3 of 230

Ammeter

A device used to measure electric current - It must be placed in series and ideally have zero resistance

4 of 230

Ampere

The base SI unit of electric current, symbol A, defined as the current flowing in two parallel wires in a vacuum 1m apart such that there is an attractive force of 2.0x10-7N per metre length of wire between them

5 of 230

Amplitude (waves)

The maximum displacement from the equilibrium position (can be positive or negative)

6 of 230

Angle of Incidence

The angle between the direction of travel of an incident wave and the normal at a boundary between two media

7 of 230

Angle of Reflection

The angle between the direction of travel of a reflected wave and the normal at a boundary between two media

8 of 230

Anion

A negatively charged ion, one which is attracted to an anode

9 of 230

Anode

A positively charge electrode

10 of 230

Antiparallel (vectors)

In the same line but opposite directions

11 of 230

Antiphase

Particles oscillating completely out of step with each other (one reaches its maximum positive displacement as the other reaches its maximum negative displacement) are in antiphase

12 of 230

Archimedes' Principle

The upthrust on an object in fluid is equal to the weight of fluid it displaces

13 of 230

Average speed

The rate of change in distance calculated over a complete journey

14 of 230

Average Velocity

The change in displacement Δs for a journey divided by the time taken Δt; Δs/Δt

15 of 230

Base Unit

One of seven units that form the building blocks of the SI measurement system

16 of 230

Battery

A collection of cells that transfers chemical energy into electrical energy

17 of 230

Braking Distance

Distance travelled by a vehicle from the time the brakes are applied until the vehicle stops.

18 of 230

Breaking Strength

The stress value at the point of fracture, calculated by dividing the breaking force by the cross-sectional area

19 of 230

Brittle

Property of a material that does not show plastic deformation and deforms very little (if at all) under high stress

20 of 230

Capacitor

A component that stores charge, consists of two plates separated by an insulator (dielectric)

21 of 230

Cathode

A negatively charged electrode

22 of 230

Cation

A positively charged ion, one which is attracted to a cathode

23 of 230

Cell

A device that transfers chemical energy into electrical energy

24 of 230

Centre of gravity

An imaginary point at which the entire weight of an object appears to act.

25 of 230

Centre of Mass

A point through which any externally applied force produces straight-line motion but no rotation

26 of 230

Charge Carrier

A particle with charge that moves through a material to form an electric current - for example, an electron in a metal wire

27 of 230

Closed System

An isolated system that has no interaction with its surroundings

28 of 230

Coherence

Two wave sources, or waves, that have a constant phase difference

29 of 230

Component

One of the two perpendicular vectors obtained by resolving a vector

30 of 230

Compression

The decrease in length of an object when a compressive force is exerted on it

31 of 230

Compression (waves)

A moving region in which the medium is denser or has higher pressure than the surrounding medium

32 of 230

Compressive deformation

A change in the shape of an object due to compressive forces

33 of 230

Compressive force

Two or more forces together that reduce the length or volume of an object

34 of 230

Conservation of charge

A conservation law which states that electric charge can neither be created nor destroyed - the total charge in any interaction must be the same before and after the interaction

35 of 230

Constant speed

Motion in which the distance travelled per unit time stays the same

36 of 230

Constant velocity

Motion in which the change in displacement per unit time stays the same

37 of 230

Constructive interference

Superposition of two waves in phase so that the resultant wave has greater amplitude than the original waves

38 of 230

Conventional current

A model used to describe electric current in a circuit - travels from positive to negative - the direction in which positive charges would travel

39 of 230

Coulomb

The derived SI unit of electrical charge, symbol C - 1 coulomb of electric charge passes a point in one second when there is an electric current of one ampere (1C = 1As)

40 of 230

couple

A pair of equal and opposite forces acting on a body, but not in the same straight line

41 of 230

Critical Angle

The angle of incidence at the boundary between two media that will produce an angle of refraction of 90

42 of 230

Crystallography

A method for determining the structure of a substance by studying the interefence patterns produced by waves passing through a crystal of the substance

43 of 230

de Broglie Equation

An equation relating the wavelength and the momentum of a particle (wavelength=h/p)

44 of 230

Density

The mass per unit volume of a substance

45 of 230

Derived Quantity

A quantity that comes from a combination of base units

46 of 230

Derived Unit

A unit used to represent a derived quantity, such as N for force

47 of 230

Destructive Interference

Superposition of two waves in antiphase so that the waves cancel each other out and the resultant wave has smaller amplitude than the original waves

48 of 230

Diffraction

The phenomenon in which waves passing through a gap or around an obstacle spread out

49 of 230

Diode

A semiconductor component that allows current only in one particular direction

50 of 230

Displacement

The distance travelled in a particular direction - it is a vector with magnitude and a direction

51 of 230

Displacement (waves)

The distance from the equilibrium position in a particular direction - displacement is a vector, so it has a positive or a negative

52 of 230

Drag force

The resistive force exerted by a fluid on an object moving through it

53 of 230

Ductile

Property of a material that has a large plastic region in a stress-strain graph, so can be drawn into wires

54 of 230

Efficiency

The ratio of useful output energy to total input energy, often expressed as a percentage

55 of 230

Elastic Deformation

A reversible change in the shape of an object due to a compressive or tensile force - removal of stress or force will return the object to its original shape and size (no permanent strain)

56 of 230

Elastic Limit

The value of stress or force beyond which the elastic deformation becomes plastic deformation, and the material or object will no longer return to its original shape and size when stress or force is removed

57 of 230

Elastic potential Energy

The energy stored in an object because of its deformation

58 of 230

Electric Charge

A physical property, symbol Q, either positive or negative, measured in coulombs, C, or as relative charge

59 of 230

Electric Current

The rate of flow of charge, symbol I, measured in amperes, A; normally a flow of electrons in metals or a flow of ions in electrolytes

60 of 230

Electricity meter

A device that measures the electrical energy supplied in kWh to a house from the grid

61 of 230

Electrolyte

A liquid containing ions that are free to move and so conduct electricity

62 of 230

Electromagnetic Spectrum

The full range of frequencies of electromagnetic waves, from gamma rays to radio waves

63 of 230

Electromagnetic Wave

Transverse waves with oscillating electric and magnetic field components, such as light and X-rays, that do not need a medium to propagate - they travel at a speed of 3.0x10^8m/s in a vacuum

64 of 230

Electromotive force (E.M.F.)

The work done on the charge carriers per unit charge, symbol V, unit volt, V, measured across a cell, battery or power supply

65 of 230

Electron gun

A device that uses a large accelerating potential difference to produce a narrow beam of electrons

66 of 230

Electronvolt

A derived unit of energy used for subatomic particles and photons, defined as the energy transferred to or from an electron when it passes through a potential difference of 1V; 1eV os equivalent to 1.6x10^-19 J

67 of 230

Elementary charge

The electric charge equivalent to the charge on a proton, 1.6x10^-19C; symbol e

68 of 230

Energy

The capacity for doing work, measured in joules, J

69 of 230

Equilibrium

A body is in equilibrium when the net force and net moment acting on it are zero

70 of 230

Equilibrium position (waves)

The resting position for particles in the medium

71 of 230

Extension

The increase in length of an object when a tensile force is exerted on it

72 of 230

Filament Lamp

An electrical component containing a narrow filament of wire that transfers electrical energy into heat and light

73 of 230

Fluid

A substance that can flow, including liquids and gases

74 of 230

Force

A push or pull on an object, measured in newtons, N

75 of 230

Force constant

A quantity determined by dividing force by extension (or compression) for an object obeying Hooke's law - called constant of proportionality k in Hooke's Law, measured in Nm-3

76 of 230

force-extension graph

A graph of force against extension (or compression), with the area under the graph equal to the work done on the material

77 of 230

Force-time Graph

A graph of net force against time, with the area under the graph equal to the impulse

78 of 230

Free Electron

An electron in a metal that is not bound to an atom and is free to move — sometimes called a delocalised electron

79 of 230

Free Fall

The motion of an object accelerating under gravity with no other force acting on it

80 of 230

Free-body Diagram

A diagram that represents the forces acting on a single object

81 of 230

Frequency

The number of wavelengths passing a given point per unit time

82 of 230

Fundamental Frequency

The lowest frequency at which an object (e.g., an air column in a pipe or a string fixed at both ends) can vibrate

83 of 230

Fundamental mode of vibration

A vibration at the fundamental frequency

84 of 230

Gamma Rays

Short-wavelength electromagnetic waves, with wavelengths from x10^−10 m to x10^−16 m

85 of 230

Gold Leaf electroscoe

A device with a metallic stem and a gold leaf that can be used to identify and measure electric charge — a device that was historically used as a voltmeter for measuring large voltages

86 of 230

Gradient

In a graph, the change in the vertical axis quantity divided by the corresponding change in the horizontal axis quantity

87 of 230

Gravitational Potential Energy

The capacity for doing work as a result of an object’s position in a gravitational field.

88 of 230

Harmonic

A whole-number multiple of the fundamental frequency.

89 of 230

Hooke's Law

The force applied is directly proportional to the extension of the spring unless the limit of proportionality is exceeded.

90 of 230

Hysteresis Loop

A loop-shaped plot obtained when, for example, loading and unloading a material produce different deformations.

91 of 230

Impulse

The area under a force–time graph — the product of force and the time for which the force acts.

92 of 230

In-phase

Particles oscillating perfectly in time with each other (reaching their maximum positive displacement at the same time) are in phase.

93 of 230

Inelastic Collision

A collision in which kinetic energy is lost.

94 of 230

Infrared Waves

Electromagnetic waves, with wavelengths from x10^−3 m to 7 × 10^−7 m

95 of 230

Instantaneous Speed

The speed at the moment it is measured — speed over an infinitesimal interval of time.

96 of 230

Intensity (waves)

The radiant power passing through a surface per unit area.

97 of 230

Interference

Superposition of two progressive waves from coherent sources to produce a resultant wave with a displacement equal to the sum of the individual displacements from the two waves.

98 of 230

Interference Pattern

A pattern of constructive and destructive interference formed as waves overlap.

99 of 230

Internal Resistance

The resistance of a source of e.m.f. (e.g a cell) due to its construction, which causes a loss in energy/voltage as the charge passes through the source, symbol r, SI unit ohm Ω.

100 of 230

Ion

An atom that has either lost or gained electrons and so has a net charge.

101 of 230

Ionic Solution

An ionic compound dissolved in a liquid to form an electrolyte.

102 of 230

I-V characteristic

A description of the relationship between the electric current in a component and the potential difference across it — in most cases this is usually in the form of a simple graph of I against V.

103 of 230

Kilowatt-hour

A derived unit of energy, most often associated with paying for electrical energy, symbol kWh (1 kWh = 3.6 MJ). Energy in kWh can be calculated by multiplying the power in kW by the time in hours.

104 of 230

Kinetic Energy

The energy associated with an object as a result of its motion.

105 of 230

Kirchoff's First Law

At any point in an electrical circuit, the sum of currents into that point is equal to the sum of currents out of that point, electrical charge is conserved.

106 of 230

Kirchoff's Second Law

In a closed loop of an electrical circuit, the sum of the e.m.f.s is equal the sum of the p.d.s

107 of 230

Law of Reflection

The angle of incidence is equal to the angle of reflection.

108 of 230

Light-Dependent Resistor

An electrical component with a resistance that decreases as the light intensity incident on it increases

109 of 230

Light-Emitting Diode

A type of diode that emits light when it conducts electricity.

110 of 230

Limit of Proportionality

The value of stress or force beyond which stress is no longer directly proportional to strain.

111 of 230

Linear Momentum

A property of an object travelling in a straight line, the product of its mass and velocity, measured in kg m s−1 or N s.

112 of 230

Loading (electrical circuits)

Connecting a component or a device across the terminals of a source of e.m.f. or across another component.

113 of 230

Loading curve

A force–extension graph.

114 of 230

Longitudinal Wave

A wave in which the medium is displaced in the same line as the direction of energy transfer — oscillations of the medium particles are parallel to the direction of the wave travel

115 of 230

Lost Volts

The potential difference across the internal resistor of a source of e.m.f.

116 of 230

Mass

s Amount of matter, a base quantity measured in kilograms, kg

117 of 230

Maximum (waves)

The point of greatest amplitude in an interference pattern, produced by constructive interference

118 of 230

Mean Drift Velocity

The average velocity of electrons as they move through a wire, symbol v, unit ms−1.

119 of 230

Microwaves

Long-wavelength electromagnetic waves, with wavelengths from x10^−1 m to x10^−3 m.

120 of 230

Minimum (waves)

The point of least amplitude in an interference pattern, produced by destructive interference.

121 of 230

Moment

The product of force and perpendicular distance from a pivot or stated point.

122 of 230

Monochromatic light

Light of a single frequency.

123 of 230

Negative charge

One type of electric charge; negatively charged objects attract positively charged ones, and repel other negative charges.

124 of 230

Negative Temperature Coefficient

A relationship in which a variable decreases as temperature increases, for example the resistance of NTC thermistors.

125 of 230

Newton's first law of motion

A body will remain at rest or continue to move with constant velocity unless acted upon by a resultant force.

126 of 230

Newton's Second Law of Motion

The rate of change of momentum of an object is directly proportional to the resultant force and takes place in the direction of the force.

127 of 230

Newton's Third Law of Motion

When two objects interact, each exerts an equal but opposite force on the other during the interaction.

128 of 230

Node

For a stationary wave, a point where the amplitude is always zero.

129 of 230

Non-ohmic Component

A component that does not obey Ohm’s law, e.g filamant lamp and diode.

130 of 230

Normal

An imaginary line perpendicular to a surface such as the boundary between one medium and another (e.g., air and glass).

131 of 230

Normal Contact Force

The force exerted by a surface on an object, which acts perpendicularly to the surface.

132 of 230

Number density

The number of free electrons per cubic metre of a material, symbol n, unit m−3

133 of 230

Ohm

The derived SI unit of resistance, symbol Ω — defined as the resistance of a component that has a potential difference of 1 V per unit ampere.

134 of 230

Ohm's Law

The potential difference across a conductor is directly proportional to the current in the component as long as its temperature remains constant

135 of 230

Ohmic Conductor

A conductor that obeys Ohm’s law

136 of 230

Optical Fibre

A fibre made of glass designed with a varying refractive index in order to totally internally reflect pulses of visible or infrared light travelling through it

137 of 230

Oscilloscope

An instrument that displays an electrical signal as a voltage against time trace on a screen

138 of 230

Out of Phase

Particles that are neither in phase, nor in antiphase, are out of phase.

139 of 230

Parallel (vectors)

In the same line and direction.

140 of 230

Parallel Circuit

A type of branching electrical circuit in which there is more than one path for the current — components in parallel have the same potential difference.

141 of 230

Partially Polarised

Description of a transverse wave in which there are more oscillations in one particular plane, but the wave is not completely plane polarised — occurs when transverse waves reflect off a surface.

142 of 230

Path Difference

The difference in the distance travelled by two waves from the source to a specific point.

143 of 230

Peak

The maximum positive amplitude of a transverse wave.

144 of 230

Perfectly Elastic Collision

A collision in which no kinetic energy is lost.

145 of 230

Period (waves)

The time taken for one complete wavelength to pass a given point.

146 of 230

Phase Difference

The difference between the displacements of particles along a wave, or the difference between the displacements of particles on different waves, measured in degrees or radians.

147 of 230

Photoelectric Effect

t The emission of photoelectrons from a metal surface when electromagnetic radiation above a threshold frequency is incident on the metal.

148 of 230

Photoelectric Effect Equation

Einstein’s equation relating the energy of a photon, the work function of a metal, and the maximum kinetic energy of any emitted photoelectrons.

149 of 230

Photoelectrons

Electrons emitted from the surface of a metal by the photoelectric effect.

150 of 230

Photon

A quantum of electromagnetic energy — photon energy E is given by E = hf, where h is the Planck constant and f is the frequency of the electromagnetic radiation.

151 of 230

Pivot

A point about which a body can rotate.

152 of 230

Planck's Constant

Symbol h, an important constant in quantum mechanics, 6.63 × 10−34 J s.

153 of 230

Plane Polarised

Description of a transverse wave in which the oscillations are limited to only one plane.

154 of 230

Plastic Deformation

An irreversible change in the shape of an object due to a compressive or tensile force — removal of the stress or force produces permanent deformation.

155 of 230

Plumb-bob

A string with a weight used to provide a vertical reference line.

156 of 230

Polarisation

The phenomenon in which oscillation of a transverse wave are limited to only one plane.

157 of 230

Polarity

The type of charge (positive or negative) or the orientation of a cell relative to a component.

158 of 230

Polycrystalline Graphite

Thin layers of graphite with regularly arranged carbon atoms in different orientations.

159 of 230

Polymeric

Description of a material comprising of long-chain molecules, such as rubber, which may show large strains.

160 of 230

Positive (charge)

One type of electric charge — positively charged objects attract negatively charged ones, and repel other positive charges.

161 of 230

Potential Difference

Defined as the energy transferred from electrical energy to other forms (heat, light, etc.) per unit charge.

162 of 230

Potential Divider

An electrical circuit designed to divide the potential difference across two or more components (often two resistors) in order to produce a specific output.

163 of 230

Potentiometer

An electrical component with three terminals and some form of sliding contact that can be adjusted to vary the potential difference between two of the terminals.

164 of 230

Power

The rate of work done, measured in watts, W.

165 of 230

Prefix

A word or letter placed before another one, for example, 5.0 km is 5.0 × 10^3 m

166 of 230

Pressure

The force exerted per unit cross-sectional area, measured in pascals, Pa.

167 of 230

Principle of conservation of energy

The total energy of a closed system remains constant — energy cannot be created nor can it be destroyed.

168 of 230

Principle of Conservation of Momentum

Total momentum of a system remains the same before and after a collision.

169 of 230

Principle of moments

For a body in rotational equilibrium, the sum of the anticlockwise moments about a point is equal to the sum of the clockwise moments about the same point.

170 of 230

Principle of superposition of waves

s When two waves meet at a point the resultant displacement at that point is equal to the sum of the displacements of the individual waves.

171 of 230

Progressive waves

A wave in which the peaks and troughs, or compressions and rarefactions, move through the medium as energy is transferred.

172 of 230

Projectile

An object that is thrown or propelled on the surface of the Earth.

173 of 230

P-waves

Primary waves — longitudinal waves that travel through the Earth from an earthquake.

174 of 230

Pythagoras' Theorem

The square of the length of the hypotenuse of a right-angled triangle equals the sum of the squares of the lengths of the other two sides.

175 of 230

Quantisation

The availability of some quantities, such as energy or charge, only in certain discrete values.

176 of 230

Quantity

A property of an object, substance, or phenomenon that can be measured.

177 of 230

Quantum Mechanics

The branch of physics dealing with phenomena on the very small scale, often less than the size of an atom.

178 of 230

Radiowaves

Long-wavelength electromagnetic waves, with wavelengths greater than x10−1 m

179 of 230

Rarefaction

A moving region in which the medium is less dense or has less pressure than the surrounding medium.

180 of 230

Ray

A line representing the direction of energy transfer of a wave, perpendicular to the wavefronts.

181 of 230

Reflection

The change in direction of a wave at a boundary between two different media, so that the wave remains in the original medium

182 of 230

Refraction

The change in direction of a wave as it changes speed when it passes from one medium to another.

183 of 230

Refractive Index

The refractive index of a material n=c/v, where c is the speed of light through a vacuum and v is the speed of light through the material

184 of 230

Relative Charge

A simplified measurement of the electric charge of a particle or object, measured as multiples of the elementary charge.

185 of 230

Resistance

A property of a component calculated by dividing the potential difference across it by the current in it, symbol R, unit ohm, Ω.

186 of 230

Resistivity

A property of a material, measured in Ω m, defined as the product of the resistance of a component made of the material and its cross-sectional area divided by its length.

187 of 230

Resistor

An electrical component that obeys Ohm’s law, transferring electrical energy to thermal energy.

188 of 230

Resistor Circuit

Two or more resistors arranged to provide a specific resistance.

189 of 230

Resolving a Vector

Splitting a vector into two component vectors perpendicular to each other.

190 of 230

Restoring Force

A force that tries to return a system to its equilibrium position.

191 of 230

Resultant Vector

A single vector that has the same effect as two or more vectors added together

192 of 230

Scalar quantity

A quantity with magnitude (size) but no direction.

193 of 230

Semiconductor

A material with a lower number density than a typical conductor, for example silicon.

194 of 230

Series

An arrangement of electrical components connected end-to-end that means that the current is the same in each component.

195 of 230

Series Circuit

A type of electrical circuit where the components are connected end-to-end SI Système International d’Unités (International System of Units).

196 of 230

Standing Wave

A wave that remains in a constant position with no net transfer of energy and is characterised by its nodes and antinodes — also called a stationary wave.

197 of 230

Stiffness

The ability of an object to resist deformation.

198 of 230

Stopping Distance

The total distance travelled from the time when a driver first sees a reason to stop to the time when the vehicle stops, the sum of the thinking distance and the braking distance.

199 of 230

Strong Material

A material with a large value for the ultimate tensile strength.

200 of 230

Superconductivity

A phenomenon in which the resistivity of a material falls to almost zero when the material is cooled below a certain temperature.

201 of 230

Superpostion

Overlap of two waves at a point in space.

202 of 230

S-waves

Secondary waves: transverse waves that travel through the Earth from an earthquake.

203 of 230

Tensile Deformation

A change in the shape of an object due to tensile forces.

204 of 230

Tensile Force

Equal and opposite forces acting on a material to stretch it.

205 of 230

Tensile strain

The extension per unit length, a dimensionless quantity.

206 of 230

Tensile Stress

The force per unit cross-sectional area, measured in Pa.

207 of 230

Tension

The pulling force exerted by a string, cable, or chain on an object.

208 of 230

Terminal pd

The potential difference across an electrical power source — when there is no current this is equal to the e.m.f. of the source, but if there is a current in the source this is equal to the e.m.f. minus the lost volts.

209 of 230

Terminal Velocity

The constant speed reached by an object when the drag force (and upthrust) is equal and opposite to the weight of the object.

210 of 230

Thermionic Emission

The emission of electrons from the surface of a hot metal wire.

211 of 230

Thermistor

An electrical component that has a resistance that decreases as the temperature increases (a negative temperature coefficient).

212 of 230

Thinking Distance

The distance travelled by a vehicle from when the driver first perceives a need to stop to when the brakes are applied.

213 of 230

Threshold Frequency

The minimum frequency of the electromagnetic radiation that will cause the emission of an electron from the surface of a particular metal — symbol ƒ0, measured in Hz.

214 of 230

Threshold Voltage

The minimum potential difference at which a diode begins to conduct.

215 of 230

Time of Flight

The time taken for an object to complete its motion.

216 of 230

Timebase

The time interval represented by one horizontal square on an oscilloscope screen.

217 of 230

Torque

The product of one of the forces of a couple and the perpendicular distance between the forces.

218 of 230

Total Internal Reflection

The reflection of all light hitting a boundary between two media back into the original medium when the light is travelling through the medium with the higher refractive index and the incidence angle at the boundary is greater than the critical angle

219 of 230

Transverse wave

A wave in which the medium is displaced perpendicular to the direction of energy transfer — the oscillations of medium particles are perpendicular to the direction of travel of the wave.

220 of 230

Triangle of Forces

Three forces acting at a point in equilibrium, represented by the sides of a triangle.

221 of 230

Trough

The maximum negative amplitude of a transverse wave .

222 of 230

Ultimate Tensile Strength

The maximum stress that a material can withstand before it breaks.

223 of 230

Ultraviolet

Electromagnetic waves, with wavelengths from 4 × 10 ^−7m to 10 ^−8m

224 of 230

Uniform Gravitational Field

A gravitational field in which the field lines are parallel and the value for g remains constant .

225 of 230

Unpolarised

Description of a transverse wave in which the oscillations occur in many planes.

226 of 230

Upthrust

The upward buoyant force exerted on a body immersed in a fluid.

227 of 230

Vector Quantity

A quantity with magnitude (size) and direction.

228 of 230

Vector Triangle

A triangle constructed to scale to determine the resultant of two vectors.

229 of 230

Velocity

A vector quantity equal to the rate of change of displacement

230 of 230

## Other cards in this set

### Card 2

#### Front

The rate of change of velocity of an object falling in a gravitational field. Symbol g

#### Back

Acceleration of free fall

### Card 3

#### Front

Drag or resistive force experienced by objects moving through air

#### Back

### Card 4

#### Front

A device used to measure electric current - It must be placed in series and ideally have zero resistance

#### Back

### Card 5

#### Front

The base SI unit of electric current, symbol A, defined as the current flowing in two parallel wires in a vacuum 1m apart such that there is an attractive force of 2.0x10-7N per metre length of wire between them

#### Back

## Similar Physics resources:

0.0 / 5

0.0 / 5

0.0 / 5

## Comments

No comments have yet been made