Current Electricty

Question 1

A good insulator

Answer 1

Does not allow electric current to flow

Question 2

A closed circuit

Answer 2

Is needed for a current to flow, if there is a break in a current then the current won’t flow.

Question 3

Energy Provided

Answer 3

By a battery or a power pack, it is needed to move the current around the circuit.

Question 4

The battery pumps electrons

Answer 4

From the negative end around a circuit

Question 5

The electrons are attached

Answer 5

Back to the positive end of the battery.

Question 6

Potential difference

Answer 6

The differences in electrical pressure between the positive and negative ends of a battery/power pack

Question 7

An Electric current

Answer 7

Is caused by the flow of electrons through a good conductor such as metal.

Question 8

Current

Answer 8

Symbol: I
Unit: ampere
Unit symbol: A
Measured using: ammeter

Question 9

Potential difference/ voltage

Answer 9

Symbol: V
Unit: voltage
Unit symbol: V
Measured using: voltmeter

Question 10

Resistance

Answer 10

Symbol: R
Unit: Ohm
Unit symbol: omega
Measured using: Ohmmeter

Question 11

Bulbs in series

Answer 11

If a bulb in a series blows, none of them turn on.
The same amount of current flows through each bulb in the series.
The voltage is split up, depending on the size of the bulb.

Question 12

Bulbs in parallel

Answer 12

The lights in your house are connected in parallel so if your bedroom bulb blows you kitchen light will stay on.
The current is splint between the bulbs, if they are the same size, then the current is split evenly.
The same voltage flows through each bulb, so they so they are brighter than those in series.

Question 13

Mains supply

Answer 13

Is A.C

It flows at a potential difference of 230 Volts

Question 14

Fuse

Answer 14

A fuse is a safety device that prevents a circuit from overheating. It will melt when too hot therefore breaking the circuit

Question 15

Circuit breaker

Answer 15

A circuit breaker is used in the fuse board of the home, and this trips, to the stop of the flow of current from entering the house.

Question 16

Why is a circuit breaker preferable

Answer 16

When a fuse blows it has to be replaced, modern houses have circuit breakers which act like a Bimetallic strip and simply switch off the current if it gets too big

Question 17

Live wire

Answer 17

Is brown and carries most electricity it is connected to the plugs fuse on the right hand side

Question 18

Neutral wire

Answer 18

Is blue and is connected to the left hand side

Question 19

Earth wire

Answer 19

Is a safety wire, no electricity flows in the earth wire unless the appliance it is attached to becomes “live” e.g a toaster, in this case the earth wire would carry the current to the earth instead of electrocuting you if you touch the toaster