Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physics A Level > 3.5.1 Electricity > Flashcards

3.5.1 Electricity Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

Equation that connects V, I and R.

A

V = I R

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is V, units?

A

Voltage, volts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is I, units?

A

Current, amps.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is R, units?

A

Resistance, ohms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Equation that connects R, ρ, L and A.

A

R = ρ L / A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is ρ, units?

A

Resistivity, ohm metre.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is L, units?

A

Length, metres.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What A, units?

A

Cross sectional area, metres squared.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the equation that connects P, I and V?

A

P = I V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is P, units?

A

Power, watts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the equation that connects P, V and R?

A

P = V^2 / R

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the equation that connects P, I and R?

A

P = I^2 R.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the equation for Q, I and t?

A

Q = I t

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is Q, units?

A

Charge, coulombs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is t, units?

A

Time, seconds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

From which end of the battery does the current flow?

A

Negative to positive.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does the exam board call the flow of electrons from neg to pos?

A

Conventional current.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

To make the electrons flow they have to flow to a ____ potential?

A

Lower.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

If you subtract the lower potential from the higher potential, what do you get?

A

Potential difference.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

P.d is referred to as what?

A

Voltage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The greater the voltage of a battery the _____ the current in a circuit?

A

Bigger.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Something that causes difficulty in electrons flowing down a wire is called a _____?

A

Resistance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is Ohm’s law?

A

The current flowing through a metallic conductor is directly proportional to the potential difference applied across it at a constant temp.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

V is directly proportional to _?

A

I.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

An ammeter is used to measure ____?

A

Current.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

An ammeter is always connected in ____?

A

Series.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the ammeter connected in series to?

A

The resistor or component.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

A voltmeter is used to measure ________?

A

Potential difference.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

A voltmeter is always connected in ____?

A

Parallel.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the voltmeter connected in parallel to?

A

The resistor or component.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the definition of potential difference?

A

The potential difference between two points is the amount of energy transformed when one coulomb of charge is moved between the two points.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the equation that connects W, Q and V?

A

W = Q V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

In a series circuit the current in that particular circuit will be the ____ at every point in the circuit.

A

Same.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

In a series circuit the p.d across each resistor is ____?

A

Different.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

In a series circuit the p.d across each resistor is ____?

A

Different.

36
Q

What does the p.d all add up to in a circuit?

A

The battery voltage.

37
Q

In a series circuit V = __________?

A

V1 + V2 + V3`

38
Q

In a parallel circuit the p.d across each branch in that particular circuit will be ____?

A

Same.

39
Q

In a parallel circuit the current in each branch may be _____?

A

Different.

40
Q

In a parallel circuit all the currents add up to the ________?

A

Supply current.

41
Q

In parallel I =

A

I1 + I2 + I3

42
Q

What is Kirchoff’s first law?

A

At any junction in a circuit the sum of the current flowing into the junction is equal to the sum of the current flowing away from it.

43
Q

What is Kirchoff’s second law?

A

In any complete loop of a circuit the sum of the sum of p.d’s equals the source p.d.

44
Q

In a series circuit what does Rtotal = ?

A

R1 + R2 + R3

45
Q

In a parallel circuit what does 1/Rtotal = ?

A

1/R1 + 1/R2 + 1/R3

46
Q

What is the equation that connects W, Q and V?

A

W = Q V

47
Q

What is W, unit?

A

Work done, joules.

48
Q

What is the equation that connects W, P and t?

A

W = P t.

49
Q

When a current flows through a circuit some energy is transformed into ____?

A

Heat.

50
Q

When 2+ resistors are connected in series the total p.d is _____ between them.

A

Divided.

51
Q

In a series circuit the largest resistor has the _______ p.d across it.

A

Largest.

52
Q

In a series circuit the individual p.ds are the ____ as the power supply.

A

Same.

53
Q

What does the current/voltage graph look like for a resistor?

A

Straight line through origin to the right, directly proportional.

54
Q

What does the current/voltage graph look like for a filament lamp?

A

S shape, to the right, intersecting origin.

55
Q

What does the current/voltage graph look like for a diode?

A

Flat then curved up in the upper right quadrant.

56
Q

What is the quantity that describes how restive a material is?

A

Resistivity.

57
Q

If you get measurements for wire in mm what do you do?

A

Convert, x10^-3.

58
Q

What does EMF stand for?

A

Electromotive force.

59
Q

Define EMF.

A

The E.M.F of a cell is the voltage across the terminals of a cell when no current is flowing through it.

60
Q

What is the internal resistance (r)?

A

The resistance of the cell itself.

61
Q

How is internal resistance represented in a circuit diagram?

A

As a circle with r in it around the cell.

62
Q

Define electric current.

A

The rate of flow of charge in a wire or component.

63
Q

In what everyday appliances will you find a variable resistor/rheostat?

A

Dimmer switches, volume control.

64
Q

What is a superconductor?

A

A wire or device that is made of a material that has 0 resistivity and below a critical temp.

65
Q

When would a superconductor lose its superconductivity?

A

If it’s temp is raised above critical temp.

66
Q

What are superconductors used to make?

A

High power electromagnets, used in MRI scanners and particle accelerators.

67
Q

What components can we see in potential divider circuits?

A

Variable resistors, thermistors, LDRs.

68
Q

What can we use potential divider circuits for?

A

Control of light levels, control of temp.

69
Q

Define terminal p.d.

A

T.P.D is the voltage that a cell has when current is flowing through it and an external resistor.

70
Q

What is the equation connecting ℰ, I, R and r?

A

ℰ = I (R + r)

71
Q

What is ℰ, units?

A

EMF, J/C

72
Q

What is the expanded form of ℰ = I (R + r)?

A

ℰ = IR + Ir

73
Q

What is Ir sometimes referred to as?

A

Lost volts.

74
Q

What is Ir?

A

P.d across internal resitor.

75
Q

What is IR?

A

P.d across resistor.

76
Q

Vout = ?

A

Vin x R2 / R1 + R2

77
Q

What is a regular thermistor called?

A

Negative temperature coefficient.

78
Q

What happens as temp decreases for a NTC thermistor?

A

Res increases.

79
Q

Why would we use a steel core for cables?

A

Increase mechanical strength.

80
Q

P.d is proportional to what?

A

R.

81
Q

Sum of p.d = ?

A

EMF

82
Q

As light decreases LDR resistance …?

A

Increases.

83
Q

More power dissipates in what circuits, why?

A

Parallel, smallest R.

84
Q

Is the coulomb an SI unit?

A

Nope.

85
Q

Resolution is what?

A

The smallest dectectable change by a measuring system.

86
Q

What is precision?

A

Number of d.p.

87
Q

Define potentioal diviofser circuit.

A

A combination of resistors in series connected across a voltage source (to produce a required pd) .

Physics A Level (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions