# Electric circuits (topic 10) Flashcards Preview

## Physics GCSE > Electric circuits (topic 10) > Flashcards

Flashcards in Electric circuits (topic 10) Deck (46)
1
Q

How are voltmeters arranged in a circuit?

A

in parallel around a component

2
Q

WHat does the diode symbol look like?

A

a back skip button in a circle

3
Q

What does a resistor symbol look like?

A

a rectangle

4
Q

What does a variable resistor symbol look like?

A

A rectangle with an arrow point diagonally upwards

5
Q

What does a fuse symbol look like?

A

a rectangle with a line through the middle

6
Q

What is the current?

A

The rate of electron flow

7
Q

What happens to the current in a series circuit at different point in the circuit?

A

Stays the same

8
Q

What happens to the current in a parallel circuit when the amp meter is in different places?

A

Changes as the current is split equally down the different paths.

9
Q

What is potential difference?

A

A potential difference, also called voltage, across an electrical component is needed to make a current flow through it.

10
Q

What is Vt equal to in a series circuit?

A

V1 + V2 + V3….

11
Q

What Vt equal to in a parallel circuit?

A

Vt = V1 = V2 = V3…

12
Q

What is electrical charge measured in?

A

Coulombs (C)

13
Q

What is the equation which relates charge to current and time?

A

charge = current x time

14
Q

Why does the current go down when more bulbs are added?

A

Because they feel more resistance

15
Q

How do you increase the resistance?

A

Make the wire thinner or longer as the electrons will hit more particles

16
Q

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

A

a straight diagonal line with a positive correlation

17
Q

How do you work out the gradient of a current-voltage graph?

A

change in y/change in x

18
Q

How do you work out the resistance from a current-voltage graph?

A

Voltage/current

19
Q

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

A

s shape- from one corner to the other

20
Q

What does the current-voltage graph look like for a Diode?

A

no voltage till a positive voltage and then curves upwards

21
Q

Why is there no current when the voltage is negative in the diode?

A

because the current only flows one way

22
Q

How does resistance change in a thermistor?

A

When there is a increased temperature there is less resistance

23
Q

What relates energy to current, time and potential difference?

A

energy = current x potential difference x time

24
Q

What is ohms law?

A

potential difference = current times resistance

v = I x R

25
Q

What equation relates energy voltage and charge?

A

energy= charge x voltage

26
Q

What does the current voltage graph look like for a fixed resister?

A

a straight diagonal line; as current increases, so does the voltage

27
Q

What is a thermistor?

A

a component which resistance decreases when temperature increases

28
Q

What is DC voltage?

A

when current flows constantly from positive to negative

e.g. cells and batteries

29
Q

What is AC voltage?

A

Mains electricity which produces an alternating current which continually changes direction

30
Q

What does the UK mains oscillate at?

A

50 Hz

31
Q

What does the earth wire in a plug do?

A

connects the meal parts of an appliance to the ground

32
Q

How does a fuse act as a safety device?

A

a Thin wire inside which can hold a maximum charge that the socket can take and will break if the charge exceeds that to stop to much current from flowing round the circuit or it catching fire

33
Q

How do circuit breakers act as a safety device?

A

detect a change in current and safely switch off the supply if there is too much current

34
Q

A

you can still get shocked

35
Q

What is good about circuit breakers?

A

they can be turned of quickly

-can be switched back on

36
Q

How is lightning made in a storm?

A

Clouds rub together creating static and friction. a charge is created as electrons are transferred. Lightning is made as elections jump to earth or something like that correct me

37
Q

What causes and electric shock?

A

when a build up of charge and u touch it and the electrons jump to you because you ore either relatively positive or negative

38
Q

When can static be dangerous?

A

When refuelling planes because a lot of static builds up when fuel enters the plane so it can spark to the metal on the plane and set the fuel alight.

39
Q

How can static be useful?

A

In electrostatic sprayers which charge the paint or insectide negative so that they repel from each other and spread out and attract to the object so less is wasted. they get the charge from a electrode in the nozzle.

40
Q

What is energy measured in?

A

Joules

J

41
Q

What is Power measured in?

A

Watts

W

42
Q

What is electric charge measured in?

A

Coulomb

C

43
Q

What is electric potential difference measured in?

A

Volts

V

44
Q

What is electrical resistance measured in?

A

Ohm

Ohm sign

45
Q

What is resistance? (definition)

A

the measure of how difficult it is for electricity to flow.

the resistance the electrons feel as they flow

46
Q

What is the definition of power?

A

A measure of how quickly energy is transferred.