By considering how we control our appliances in our homes, we can understand how switches and variable resistors should be included in electrical circuits.

What is the name of plug wire that switches are always connected to?

Live

Neutral

Earth

What kind of circuit is a power ring?

Series

Parallel

Lighting

What does the following circuit symbol represent?

Resistor

Variable resistor

Fuse

What is resistance a measure of?

A measure of its support for current

A measure of current

A measure of its opposition to a flow of current

What is the energy transformation inside a resistor?

Heat to electrical

Electrical to heat

Electrical to light

Which of the following is a way of increasing the current in an electrical circuit?

Increasing the voltage

Increasing the resistance

Decreasing the voltage

What happens to the resistance when more lamps are added in series?

Nothing, it stays the same

It increases

It decreases

Which of the following is the correct relationship between voltage, current and resistance?

\[\text{Resistance} = \text{voltage} \div \text{current}\]

\[\text{Resistance} = \text{current} \div \text{voltage}\]

\[\text{Resistance} = \text{voltage} \times \text{current}\]

What is the resistance of a resistor that has a voltage of \(6\, V\) and a current of \(2\, A\)?

\[3\, \Omega\]

\[12\, \Omega\]

\[0.3\, \Omega\]

What is the resistance of a lamp that has a voltage of \(9\, V\) and a current of \(1.5\, A\)?

\[13.5\, \Omega\]

\[6\, \Omega\]

\[0.17\, \Omega\]

What is the resistance of a heater that has a voltage of 230 V and a current of 10 A?

\[2300\, \Omega\]

\[0.04\, \Omega\]

\[23\, \Omega\]