C&G Electrical science and principles (202)

The watt is a measure of:

• potential difference

• power

• force

• coulomb

The volt is a measure of:

• potential difference

• power

• voltage

• coulomb

The newton is a measure of:

• potential difference

• power

• force

• volt

The prefix milli applies to:

• 10^-2

• 10^-3

• 10^-4

• 10^-6

Rearrange the formula R = ρL/A to find ρ.

• ρ = R/LA

• ρ = RA/L

• ρ = R/LA

• ρ = A/RL

A shower unit draws 20 A from a domestic 230V supply. Calculate the amount of power used.

• 4.6 kW

• 11.5 kW

• 46 kW

• 0.08 kW

The resistance of a kettle element which takes 12 A from a 230V mains supply is:

• 2.88 Ω

• 5.00 Ω

• 12.24 Ω

• 19.16 Ω

A 12Ω filament lamp was found to be taking a current of 2 A at full brilliance. The voltage across the lamp under these conditions is:

• 6 V

• 12 V

• 24 V

• 48 V

Which of the following would be considered a load?

• Motor

• Lamp

• Circuit breaker

• Switch

Water heaters use which of the following to operate?

• Heat

• Magnetism

• Chemical

• Light