Physics year 9 chapter 6- mains electricity

What is alternating current?

Current that changes direction continuously

What is direct current?

Current flowing in one direction from a battery

Cells and batteries provide…

Currents and voltages for electric circuits.

Two reasons wires are insulated.

to prevent short circuits and protect users from electrical shock.

What type of current is this?

Alternating

What is the live wire? (1 mark)

The wire which current passes through to the appliance.

What is the neutral wire? (2 marks)

The wire which current travels out of the appliance back to the power source.

What is the earth wire? (3 marks)

If there is a fault, the earth wire directs the current safely into the ground to prevent electric shock or fire as it is the path of least resistance.

What are the wire colours?

The live wire is typically brown, the neutral wire is blue, and the earth wire is green and yellow striped.

What is the live wire connected to and why?

The fuse, so that if the current gets too high the fuse melts to prevent electrical shock or appliance overheating.

How do circuit breakers work?

Increase in current causes an electromagnet to attract the armature, stopping the circuit and preventing electrical shock or appliance damage,

Give 3 reasons circuit beakers are better than fuses.

They can be reset, provide quicker response time, and do not need to be replaced after tripping.

A cell provides a circuit with…

Electrical energy.

As electrical energy is provided to a circuit, electrons receive..

an increase in kinetic energy