Brainscape's Knowledge GenomeTM

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


See full index

Physics > P2- Current Electricity > Flashcards

P2- Current Electricity Flashcards

1
Q

Opposites..

A

Attract.

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

Objects with the same electric charge..

A

Repel each other.

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

How can we calculate current?

A

I= Q/t

I= current in amperes (A).

Q= charge in coulombs (C).

t= time in seconds (s).

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

How does an insulator become negatively charged?

A

It gains electrons.

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

What circuit symbol is this?

A

Switch (open)

The switch enables the current to be switched on or off.

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

What circuit symbol is this?

A

Switch (closed)

The switch enables the current to be switched on or off.

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

What circuit symbol is this?

A

Cell

A cell is needed to push electrons around a complete circuit.

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

What circuit symbol is this?

A

Battery

A battery consists of two or more cells.

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

What circuit symbol is this?

A

Ammeter

An ammeter measures electric current.

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

What circuit symbol is this?

A

Voltmeter

A voltmeter measures potential difference (voltage).

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

What circuit symbol is this?

A

Motor

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

What circuit symbol is this?

A

Lamp

Emits light when a current passes through it.

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

What circuit symbol is this?

A

Fuse

Designed to melt if current going through it is greater than a certain amount➡️Breaks circuit

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

What circuit symbol is this?

A

Fixed resistor

Limits the current in a circuit.

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

What circuit symbol is this?

A

Variable resistor

Allows current to be varied.

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

What circuit symbol is this?

A

Light dependent resistor

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

What circuit symbol is this?

A

Diode

Allows current through in one direction only.

18
Q

What circuit symbol is this?

A

Light-emitting diode

Emits light when a current passes through it.

19
Q

What circuit symbol is this?

A

Heater

Transfers electrical energy to heat the surroundings.

20
Q

How can we calculate potential difference (voltage)?

A

V=W/Q

V= Potential difference in volts (V).

W= work done in joules (J).

Q= charge in coulombs (C).

21
Q

How can resistance be calculated?

A

R=V/I

R= resistance in ohms (Ω).

V= potential difference in volts (V).

I= current in amps (A).

22
Q

Where should voltmeters always be placed in relation with the measured component?

A

In parallel.

23
Q

What is resistance?

A

Resistance is the opposition to current flow.

24
Q

What is the unit of resistance?

A

Ohms.

25
Q

Where should ammeters be placed in relation to the measured component?

A

In series.

26
Q

What is Ohm’s law?

A

Ohm’s law states that the current through a resistor at constant temperature is directly proportional to the potential difference across the resistor.

27
Q

What does this graph show and why?

A

A current-potential difference graph for a filament light bulb.

The line is a curve because the wire gets hotter for larger currents.

28
Q

What does this graph show and why?

A

A current-potential difference graph for a diode.

The current only flows in one direction so in reverse direction the diode has very high resistance so the current is zero.

29
Q

What does this graph show?

A

A resistance-temperature graph for a thermistor.

As the temperature increases, the resistance decreases.

30
Q

What does this graph show?

A

A resistance-light intensity graph for a light-dependent resistor.

As light intensity increases, resistance decreases.

31
Q

What happens in a series circuit if one component stops working?

A

No current flows.

This is because in a series circuit, they are all connected one after the other and there is only one route for the charge to flow.

32
Q

How could you find the total potential difference in a series circuit?

A

Add all the individual potential differences.

33
Q

How could you find the total resistance in a series circuit?

A

Add all the individual resistances.

34
Q

What happens in a parallel circuit if one component stops working?

A

Current can’t flow to that one component, but can flow to all the other components.

This is because each component is connected across the supply.

35
Q

How could you find the total current in a parallel circuit?

A

Add the individual currents.

36
Q

How could you find the total voltage in a parallel circuit?

A

In a parallel circuit the potential difference is the same across each component.

37
Q

How does current depend on resistance in a parallel circuit?

A

The bigger the resistance of a component, the smaller the current is.

38
Q

What circle symbol is this?

A

Thermistor.

39
Q

Why is it important that ammeters have very low resistance?

A

So the ammeter reduces the current as little as possible.

40
Q

The resistance of the bulb increases as the potential difference across the bulb increases. Why?

A

Temperature of bulb increases.

Physics (18 decks)

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