Electricity

Question 1

What does insulation in a circuit do

Answer 1

It protects against unwanted current flow

Question 2

Double insulation

Answer 2

The whole inside of a circuit is contained in plastic meaning no current is able to touch the outer insulator

Question 3

An earth wire

Answer 3

An earth wire provides a low resistance path to the ground therefore in an event of a fault, the current is sent to the ground

Question 4

Function of a fuse

Answer 4

A fuse breaks a circuit if too much current is flowing

Question 5

Function of a circuit breaker

Answer 5

Interrupts the electrical current when it exceeds its design limitation

Question 6

Mains electricity

Answer 6

The power brought into peoples homes

Question 7

Explain use of series circuit

Answer 7

Series circuit is used in a fridge or freezer because it warns you if one part breaks. This is because all parts stop working

Question 8

Explain the uses of a parallel circuit

Answer 8

Lights in a house because if one stops working all the others continue to work

Question 9

Parallel circuit

Answer 9

One that has two or more paths for electricity to flow

Question 10

Series circuit

Answer 10

One that only has one path for current to flow

Question 11

Ohms law about current

Answer 11

Current is directly proportional to voltage and inversely proportional to resistance

Question 12

What are used as a detector if a circuit is on

Answer 12

LED’s or lamps, buzzers as they turn on when current is present

Question 13

Define current

Answer 13

The rate of flow of charge

Question 14

Why is current conserved at a junction

Answer 14

Because charge is always conserved

Question 15

In a series circuit: what is the total resistance?
What happens to voltage?
What happens to current?

Answer 15

Total resistance is the sum of all the components resistance
Voltage is shared between each component
Current is not used at and is the same throughout the circuit

Question 16

Define voltage

Answer 16

The energy transferred per unit of charge

Question 17

What is a conductor and give examples in

Answer 17

A conductor is a material that allows current to flow through them (e.g gold, aluminium (Metals))

Question 18

What is an insulator and give examples

Answer 18

An insulator is a material that doesn’t allow charge through it (e.g glass, plastic)

Question 19

What happens to like and unlike charges

Answer 19

Like charges repel and unlike charges attract

Question 20

When does the electrostatic phenomena occur

Answer 20

When two bodies accumulate electrical charges, either by induction of friction

Question 21

Dangers of electrostatic charges

Answer 21

Fuelling an aircraft there is a large build up of electrostatic charge that may make a spark to the earth. Because fuel is highly flammable it can easily ignite

Question 22

Uses of electrostatic charge

Answer 22

Photo copying: parts of the page are negatively charged, the ink is positively charged so when sprayed onto the page it sticks at those points