AOS3_2B

Which of the following statements about a resistor is incorrect?

• A resistor dissipates energy in the form of thermal energy.

• A resistor adds energy to a circuit.

• A resistor limits the flow of current in a circuit.

• A resistor reduces the rate of movement of charge.

A resistor, with resistance R = 6.0 Ω , has a current I = 1.5 A flowing through it. What is the potential difference across the resistor?

• 9 V

• 4 V

• 5 V

• 0 V

What is a device that has a constant resistance for all potential differences called?

• constant current device

• non-ohmic device

• ohmic device

• constant voltage device

Which of the following best describes the gradient of an I-V graph for such a device?

• negative and constant

• positive and constant

• positive and varying

• negative and varying

Which, if any, of the following are true for I-V graphs of ohmic devices?

• must be a horizontal line

• must pass through the origin

• must not pass through the origin

• none of the above

When a 12 V potential difference is applied across a resistor, it drives a current of 0.20 A. Determine the resistor’s resistance.

• 60 Ω

• 24 Ω

• 18 Ω

• 36 Ω

A current of 40 mA is measured by the ammeter in the circuit shown. Determine the potential difference that will be measured by the voltmeter.

• 360 V

• 0.36 V

• 3.6 V

• 36 V

I-V graphs are produced for one electrical device P.

Use the graph for device P to determine its resistance. 

• 20 Ω

• 100 Ω

• 50 Ω

• 250 Ω

I-V graphs are produced for one electrical device P.

Use the graph for device P to determine its resistance. 

• 5 Ω

• 15 Ω

• 1.7 Ω

• 0.6 Ω

3.0 A of current flows through an ohmic phone charger when an ideal 60 V source is connected. Determine the current that would flow through the charger if it was connected to an ideal 45 V source.

• 0.44 A

• 2.25 A

• 9 A

• 5 A