Practical Electricity - Safety

Which of the three wires is safe and appropriate to touch?

• Live

• Neutral

• Earth

• None. you should never poke at electrical sockets.

What is the minimum amount of current required to be lethal?

• 150 mA

• 900 mA

• 1 A

• 20 A

Label the wires

c

a

b

neutral

live

Earth

Which two wires will current be flowing through when an appliance is working correctly?

• live and Earth

• live and neutral

• neutral and Earth

Match the following wires to the correct color and potential

• Earth

• 0 V - Green wire

• Neutral

• 0 V - Blue wire

• Live

• 230 V - Brown wire

Label on the diagram, the direction of current flow when the switch is closed.

While you are preparing to iron your uniform, you noticed some damages on the cable as shown. What will be some risk if the iron is used? Explain.

Which of the following cables has the lowest resistance?

• A

• B

• C

Which of the 3 cable will produce the most heat when 2 A of current flows through?

What do you notice about the wire as the current is increased?