Flashcards in Definitions Deck (62):

1

## Principal of Conservation of Energy

### Energy may be transformed from one form into another, but it cannot be created or destroyed

2

## Principal of Conservation of mechanical energy

### The total amount of mechanical energy which the bodies in a system posses is constant, provided no external forces act

3

## Kirchhoff’s first law

###
At any junction or point of the circuit, the sum of the current going in is equal to the sum of the current going out

Conservation of charge

4

## Kirchhoff’s second law

###
The emf of a circuit is equal to the potential difference in any closed loop of a circuit

Conservation of voltage

5

## Ohm’s law

### V is proportional to I as on a graph the line would be a straight line through the origin

6

## Volt

### Energy per unit charge

7

## Coulomb

### One amp per one second

8

## The charge of an electron

### 1.6*10^-19

9

## Charge

### A property of protons and electrons equivalent to the product of current and time

10

## Potential difference

### Work done BY each unit of charge in a component converting electrical energy into other forms of energy

11

## Electromotive force

### Work done ON each unit of charge in a component converting energy from other forms into electrical energy

12

## Resistance

### The opposition to the flow of current

13

## The ohm

### A. Opponent has a resistance of one ohm when a potential difference of one volt is required to push a current of one amp through the component

14

## Power

### The rate of work done Or the work Done per unit time

15

## Kilowatt-hour

### The energy used by an appliance with a power rating of 1KW in one hour equivalent to 3.6MJ

16

## Electron density

### The number of free electrons per unit volume of a conductor

17

## Antiphase

### When the particles of two waves oscillate in the exact opposite path, when one reaches maximum positive amplitude the other reaches maximum negative amplitude

18

## Archimedes’s principle

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

19

## Braking distance

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

20

## Brittle

### A property of a material that does not show plastic deformation or become deformed at all when under stress

21

## Capacitor

### A component that stores charge, consists of two plates separated by an insulator

22

## Coherence

### Two waves that are coherent have a constant phase difference

23

## Constructive interference

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

24

## Coulomb

### The derived SI unit of electrical charge, 1 coulomb of electric charge passes a point in one second when there is an electric current of one ampere

25

## Destructive interference

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

26

## Diffraction

### Waves spreading out as they pass through a gap or around an obstacle and spread out

27

## Diode

### A semiconductor component that allows current only in one particular direction

28

## Displacement

### The distance travelled in a particular direction - it is a vector so can have positive and negative values

29

## Displacement in waves

### The distance from the equilibrium position in a particular direction

30

## Drag force

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

31

## Ductile

### Property of a material that has a large plastic region in a stress-strain graph

32

## Elastic deformation

### A reversible change in the shape of an object due to a compressive or tensile force

33

## Elastic limit

### The value of stress or force beyond which elastic deformation becomes plastic deformation and the material will no longer return to its original shape

34

## Elastic potential energy

### The energy stored in an object because of its deformation

35

## Electrolyte

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

36

## Electromagnetic spectrum

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

37

## Electronvolt

###
A derived unit of energy used for subatomic particles and photons, defined as the energy transferred to it from an electron when it passes through a potential difference of 1 volt

1eV=1.6x10^-19

38

## Energy

### The capacity for doing work, measured in joules

39

## Equilibrium

### A body is in equilibrium when the net force and net moment acting in ut are zero

40

## Extension

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

41

## Filament lamp

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

42

## Force constant

### A quantity determined by dividing force by extension (or compression) for an object obeying Hooke’s law

43

## Free electron

### An electron in a metal that is not bound to an atom and is free to move

44

## Wave frequency

### The number of wavelengths passing a given point per unit time

45

## Fundamental frequency

### The lowest frequency at which an object can vibrate

46

## Gravitational potential energy (g.p.e)

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

47

## Harmonic

### A whole-number multiple of the fundamental frequency

48

## Hooke’s law

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

49

## In phase

### Particles oscillating perfectly in time with each other reaching maximum positive and negative amplitudes at the same time

50

## Interference

### Superposition of two progressive waves from coherent sources to produce a resultant wave with a displacement equal to the vector sum of the amplitudes of the two waves

51

## Interference pattern

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

52

## Internal resistance

### The resistance of a source of e.m.f. due to its construction, which causes a loss in energy/voltage as the charge passes through the source

53

## Ion

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

54

## Kilowatt-hour

### Energy in kWh can be calculated by multiplying the power in law bf the time in hours, it is a derived unit with 1kWh=3.6MJ

55

## Kinetic energy

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

56

## Longitudinal wave

### A wave in Which the medium is displaced in the same lines as the direction of energy transfer

57

## Mean drift velocity

### The average velocity of electrons as they move through a wire

58

## Moment

### The product of a force and perpendicular distance from a pivot

59

## 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

60

## 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

61

## Newton’s third law of motion

### When two objects interact, each everts an equal and opposite force in the other

62