Electricity

Question 1

Name 3 parts of an Electrical Circuit

Answer 1

1. A source of electricity: a cell or battery
2. Conducting material: copper wires
3. A device: light bulb that changes electrical energy to light energy

Question 2

What is an electrical system?

Answer 2

All parts working together to form a useful system

Question 3

Why does most electrical systems have switches?

Answer 3

To control when the circuit is closed or open, i.e. working or not.

Question 4

What is an electrical circuit diagram?

Answer 4

Uses symbols to show how an electrical circuit is set up and where the current flows

Question 5

Give 4 symbols used in electrical circuit diagrams

Answer 5

1. Cell or battery
2. Conductor: copper wire
3. Switch
4. Device: light bulb

Question 6

Name two types of Electrical circuits and give definitions of each

Answer 6

1. Series circuits: where there is only one path for the electricity to flow through
2. Parallel circuits: where there is more than one path for electricity to flow through

Question 7

Draw a series and a parallel circuit, each with a battery, a switch and two lamps.

Question 8

Give 4 examples where your think electric circuits are used for safety and security (to solve problems).

Answer 8

1. Spotlights
2. Alarms
3. Security cameras
4. Traffic Lights

Question 9

Give 4 examples where you use electricity for everyday needs

Answer 9

1. Lighting
2. Heating
3. Cooking
4. Computers

Question 10

Why is electricity important for the economy?

Answer 10

1. Factories operate machines
2. Mining uses it for lifts and drilling
3. Farmers use it for pumping water

Question 11

Name 4 ways in which electrical energy is transformed into other forms of energy

Answer 11

1. Lamps transform electrical energy into light energy
2. Radios transform electrical energy into sound energy
   3 Heaters and stoves transform electrical energy into heat energy
3. Fans transforms electrical energy into movement (of air) energy. Also called kinetic energy.

Question 12

Name the steps for creating an electrical system

Answer 12

1. Write a “design brief” (specify) to state what problem you are going to solve with the system
2. Research and find how other people do it and why
3. Design and make the system

Question 13

Name 3 types of fossil fuels used for generating electricity

Answer 13

1. Oil: from organisms that died 100 million years ago
2. Natural gas: decomposing of organisms
3. Coal: From pressure and heat compressing fossils into coal

Question 14

Why do we say all our energy comes from the Sun?

Answer 14

The Sun gave the energy for the organisms to grow and eventually die to become the fossil fuels

Question 15

What Our main fossil fuel?

Answer 15

Coal. Power stations are build where the mines are, to save transport costs

Question 16

Describe the process for generating electricity from coal

Answer 16

1. Coal is burned in a power station
2. The heat boils water making steam to turn the turbines
3. Electric generator is turned by the turbines
4. Electricity is generated by the generator

Question 17

Why is our electricity expensive?

Answer 17

it needs an expensive electrical infrastructure: a grid of pylons, overhead wires and substations to distribute the electricity to our homes and factories

Question 18

How to save electricity

Answer 18

Use low energy lights
Use solar panels
Use solar water heaters
Switch off what you don’t need.