Topic 17 - Electricity, Ohm's Law

Which electrical quantity has the same unit as electromotive force?

• charge

• current

• potential difference

• power

How could the unit of potential difference, the volt, also be written?

• A/s

• C/A

• C/J

• J/C

What is measured by the energy dissipated when a source drives a unit charge round a complete circuit?

• electromotive force

• potential difference

• power

• resistance

What is used in an electric circuit to allow current in one direction only?

• a fuse

• an ammeter

• a diode

• a relay

What is,the current İna 5.0 Ω resistor when the potential difference between the ends of the resistor is 2.5 V?

• 0.50 A

• 2.0 A

• 2.5 A

• 12.5 A

When a p.d, of 2 V is applied across a resistor, 10 J of energy are converted. What charge flows through the resistor?

• 0.20 C

• 5.0 C

• 12 C

• 20 C

A milliammeter shows a reading of 30 mA. How much electrical charge flows through the milliammeter in 10 seconds?

• 0.3 C

• 3.0 C

• 30 C

• 300 C

When a current of 2A flows for 5 seconds through a lamp, 120W of power are used. How much charge flows through the lamp?

• 10 C

• 12 C

• 24 C

• 60 C

What is measured by the energy dissipated when a source drives a unit charge round a complete circuit?

• electromotive force

• potential difference

• power

• resistance

Which of the following changes to a wire doubles its resistance?

• A

• B

• C

• D