Brainscape's Knowledge GenomeTM

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


See full index

Physics > Mains Electricity > Flashcards

Mains Electricity Flashcards

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

What is AC current?

A

Alternating Current- current which changes direction constantly

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

What is DC current?

A

Direct current- Current which flows in only one direction through a circuit

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

How does the oscilloscope change when the current increases with AC current?

A

the amplitude increases

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

How does the oscilloscope change when the frequency increases with AC current?

A

The frequency of the wave increases

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

What does DC current look like on an oscilloscope?

A

A straight horizontal line

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

What type of current is mains electricity?

A

AC

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

What type of current is a battery?

A

DC

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

What are the colours and names of the 3 wires in a 3 pin plug?

A

Live (brown), Earth (yellow and green stripes), Neutral (blue)

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

What is the potential difference of mains electricity?

A

230V

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

When looking at a plug from above, what is the order of the 3 wires from left to right?

A

Neutral, Earth, Live

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

What is the job of the live wire?

A

It carries alternating current from the mains

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

What is the job of the neutral wire?

A

It completes the circuit

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

What is the job of the earth wire?

A

It connects to the metal casing of an appliance and the ground, so that if the live wire becomes loose and touches the casing, the appliance won’t become live and can’t shock people.

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

Why should you never touch the live wire, even when the appliance is turned off?

A

You could touch the wire before the switch, where current still flows.

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

Why should you never touch the neutral wire?

A

The appliance could have been wired the wrong way around, making the neutral wire into the live wire.

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

What is a fuse?

A

A thin wire which melts if too much current flows through it, breaking the circuit.

17
Q

What are the potential differences of the three wires?

A

Live - 230 V
Neutral - at or close to 0 V
Earth - 0 V

18
Q

What is power?

A

The rate of transfer of energy

19
Q

What is the equation connecting power, time and energy?

A

P = E / t power = energy / time

20
Q

What is the equation connecting potential difference, power and current?

A

P = I V power = current x potential difference

21
Q

What is the equation connecting charge, energy and potential difference?

A

E = Q V energy = charge x potential difference

22
Q

What is the unit of measurement for power?

A

Watts (W)

23
Q

What is the equation connecting power, resistance and current?

A

P = I^2 R power = current^2 x resistance

24
Q

what are the equations for efficiency?

A 
efficiency = useful power out / total power in
efficiency = useful energy out / total energy in
25
Q

How do you choose the correct fuse for a circuit?

A

Choose the smallest fuse size above the current of the circuit.

Physics (2 decks)

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