p5 //2

Question 1

what happens when electrical charge flows through an appliance

Answer 1

electrical energy is transferred by the appliance to another energy store

Question 2

how can you find the correct size of a fuse for an appliance

Answer 2

electrical appliances have their power rating shown on them.

Question 3

what is the potential difference of the mains supply

Answer 3

230 V

Question 4

how is the fuse chosen

Answer 4

so its current rating is slightly higher than the current through the appliance

Question 5

what happens when charge flows through a resistor

Answer 5

energy is transferred to the resistor and the thermal energy store in resistor increases so it becomes hotter and heats up its surroudings

Question 6

how is cost owed for amount of electrical energy used in a household measured

Answer 6

domestic electricity meter

Question 7

what is the equation for efficiency

Answer 7

output power
——————– x 100
input power.

or
useful energy/total input x100

Question 8

what are the wires of a three pin plug made of

Answer 8

copper as its a good electrical conductor

Question 9

what does the neutral wire do

Answer 9

completes the circuit by carrying away the current

Question 10

what does the earth wire do

Answer 10

stops the appliance casing from coming live by providing an alternate route for the current to flow away

Question 11

why can a two core cable be used for a hair dryer

Answer 11

the outer case of a hair dryer is made from plastic, which is an insulator so doesn’t need an earth wire.