P3: Circuits

Question 1

What are the units for current?

Answer 1

Amps (A)

Question 2

Identify the circuit symbol

Answer 2

Cell

Question 3

Which circuit component pushes charge (electrons) around a circuit?

Answer 3

A cell or battery

Question 4

Identify the circuit symbol

Answer 4

Bulb

Question 5

Identify the circuit symbol

Answer 5

Voltmeter

Question 6

What is meant by electrical current?

Answer 6

The amount of charge flowing per second

Question 7

Which component can we use to control whether or not current can flow in a circuit

Answer 7

A switch

Question 8

Identify the circuit symbol

Answer 8

Motor

Question 9

The charged particles that move around a circuit are called…

Answer 9

electrons

Question 10

Which component do we use to measure electric current?

Answer 10

Ammeter

Question 11

Identify the circuit symbol

Answer 11

Switch

Question 12

Identify the circuit symbol

Answer 12

ammeter

Question 13

Two or more cells make up a…

Answer 13

……..battery

Question 14

Identify the circuit symbol

Answer 14

Battery

Question 15

Identify the type of circuit shown.

Answer 15

Series Circuit

Question 16

What makes parallel circuits more useful than series circuits?

Answer 16

• If one bulb breaks, the other bulbs will stay on.
• All bulbs are the same brightness.
• You can control each bulb by putting a separate switch in each ‘branch’.

Question 17

Identify the type of circuit shown.

Answer 17

Parallel Circuit

Question 18

What happens to the current in a parallel circuit if you add more branches?

Answer 18

The current in each branch stays the same.

The total current being pushed by the battery increases.

Question 19

In which direction does current (charge per second) travel around a circuit?

Answer 19

From the positive side of a cell or battery, to the negative side (if conventional current).

From negative to positive (if talking about direction electrons travel)

Question 20

What would you notice about the readings on the three ammeters in this circuit.

Answer 20

All the readings will be the same.

Current is NOT used up

Question 21

What would happen to

• the brightness of the bulbs
• the current
• the resistance in the circuit

if another bulb was added in series

Answer 21

Bulbs - get dimmer

Current - goes down

Resistance - goes up

Question 22

If the bulbs are the same and A1 reads 6A - what would the readings on the other 3 ammeters be?

Answer 22

A1 - 6 Amps

A2 - 3 Amps

A3 - 3 Amps

A4 - 6 Amps

Question 23

If another (identical) bub was added in parallel, what would the new readings on the ammeters go up, down or stay the same?

What would happen to the brightness of the bulbs?

Answer 23

A1 - go up

A2 - stay the same

A3 - stay the same

A4 - go up

Brightness of bulbs would stay the same.

Question 24

What would happen if the LED in the circuit was turned round and reconnected.

Answer 24

It wouldn’t light up as it will only allow current to pass throught it in one direction.

Question 25

Name this component.

If this was connected in series to an LED and battery, what would happen to the brightness of the LED if light was shone on the component. Explain your answer.

Answer 25

Light Dependent Resistor (LDR)

LED would get brighter. Shining light on a LDR lowers the resistance, allowing more current through which will make the LED brighter.