Potential Divider

A cell of e.m.f. 2.0 V and negligible internal resistance is connected to the network of resistors shown.

V₁ is the potential difference between S and P. V₂ is the potential difference between S and Q.

What is the value of V₁ – V₂?

• +0.50 V

• +0.20 V

• -0.20 V

• -0.50 V

A circuit is set up with an LDR and a fixed resistor as shown.

The voltmeter reads 4 V.

The light intensity is increased.

What is a possible voltmeter reading?

• 3 V

• 4 V

• 6 V

• 8 V

A thermistor and another component are connected to a constant voltage supply. A voltmeter is connected across one of the components. The temperature of the thermistor is then reduced but no other changes are made.

In which circuit will the voltmeter reading increase?

• A

• B

• C

• D

In the circuit shown, the 6.0 V battery has negligible internal resistance. Resistors R₁ and R₂ and the voltmeter have resistance 100 kΩ.

What is the current in resistor R₂?

• 20 x 10^-6 A

• 30 x 10^-6 A

• 40 x 10^-6 A

• 60 x 10^-6 A

The unknown e.m.f. E of a cell is to be determined using a potentiometer circuit. The balance length is to be measured when the galvanometer records a null reading.

What is the correct circuit to use?

• A

• B

• C

• D