Practical Electricity [NA syllabus]

The cost of electricity is 27 cents per kWh. What is the cost of using a 1000–1200 W iron at maximum power for 45 minutes?

................... cents

Which label points to the Neutral Wire on the diagram?

An electrician has a 3 A, a 5 A, and a 10 A fuse. He is replacing a broken fuse in an appliance.

The appliance has a power rating of 1000 W and it is plugged into the mains supply, at 230 V. Determine the fuse that should be used in the appliance.

An 2 kW air-con is using 240 kWh of energy in a 30 day-month.

Calculate how long the air-con was switch on in each day.

..................... min

Which wire produces more heat?

• Thick wire

• Thin wire

• Both equally

What might happen if wires weren't insulated?

• The power source would no longer provide a source of electrons.

• We'd be in danger of harm from electric shocks.

• Current electricity would become static electricity.

• The circuit would be broken.

electric wires must be covered with ....................

• copper

• iron

• lead

• rubber

The live wire is covered with _____________ insulation.

• blue

• brown

• green and yellow stripes

• fire

Study the circuit below. Which of the points should a fuse be placed?

• A

• B

• C

• D

what is the effect of using the plug this way?

• the fuse in the plug blows

• the metal case becomes live

• the vacuum cleaner catches fire

• the vacuum cleaner does not work