Brainscape's Knowledge GenomeTM

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


See full index

Physics - Particles, quantum phenomena and electricity > Chapter 4 - Electric current > Flashcards

Chapter 4 - Electric current Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
0
Q

What formula relates charge, current and time?

A

Q=It

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

Define current

A

Rate of flow of charge (due to passage of charge particles)

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

How do you work out the number of electrons passing for a given charge?

A

Times it by the charge of the electron

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

What is the structure of an insulator?

A

Each electron is attached to the atom

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

What is the structure of a conductor?

A

Free charge carriers (electrons/ions)

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

What is the structure of semi-conductors?

A

The number of free electrons increases with temperature (as they gain more energy to break free of the shells)

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

What is the formula relating energy, voltage and charge?

A

E=VQ

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

What is the formula relating current, resistance and voltage?

A

V=IR

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

What is Ohms law?

A

V=IR

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

Define the term potential difference

A

The work done/ energy transferred per unit of charge

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

Define the term electromotive force

A

Electrical energy predicted per unit of charge passing through the source

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

What is the formula relating power, current and voltage/resistance?

A

P=IV=IIR

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

What is the formula relating power, energy and time?

A

Power = Energy/time

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

What is the formula relating resistivity, resistance, area and length?

A

resistance = (resistivity*length)/area

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

Define the term superconductor

A

A material with 0 electrical resistance

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

Define the term transition temperature

A

The temperature at which a material loses its superconducting ability

16
Q

Define the term critical temperature

A

The temperature at which and below a materials resistance = 0

17
Q

What are the applications of superconductors?

A

Efficient power lines/ cables

High power electromagnets with very strong magnetic fields

18
Q

Define the term diode

A

Very high resistance in 1 direction but very low in the other

19
Q

What happens as temperature increases on a thermistor?

A

Resistance descreases

20
Q

In metals what happens when temperature increases? Explain why

A

Resistance increases as cations have more kinetic energy so electrons cannot pass through as easily

21
Q

Why do metals have a positive temperature coefficient?

A

As temperature increases, resistance increases

22
Q

Why do semi conductors have a negative temperature coefficient?

A

As temperature increases, resistance decreases

23
Q

Why are thermistors often used as temperature sensors?

A

Its % change of resistance per kelvin is much greater than that of a metal

Physics - Particles, quantum phenomena and electricity (6 decks)

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