Topical Test 2

Which diagram best shows the pattern of field lines around a bar magnet?

• A

• B

• C

• D

Which materials are suitable to make a permanent magnet and the core of an electromagnet?

• A

• B

• C

• D

Which two electrical quantities are measured in volts?

• current and e.m.f.

• current and resistance

• e.m.f. and potential difference

• potential difference and resistance

Which of the following pieces of copper wire has the greatest electrical resistance?

• A

• B

• C

• D

A 20 Ω resistor and a 10Ω resistor are connected in parallel.

What is their combined resistance?

• less than 10Ω

• 10Ω

• 20Ω

• more than 20Ω

When electricity is transmitted over long distances, energy is wasted. How can the wasted energy be kept as small as possible?

• Keep the current in the transmission lines as large as possible.

• Keep the power supplied to the transmission lines as large as possible.

• Keep the resistance of the transmission lines as large as possible.

• Keep the voltage supplied to the transmission lines as large as possible.

• A

• B

• C

• D

A student has wires of different lengths and different diameters. The wires are all made of the same metal.

The student measures the resistance of one wire.

Which wire has a greater resistance than the wire he has measured?

• a shorter wire with a larger diameter

• a shorter wire with the same diameter

• a wire of the same length with a larger diameter

• a wire of the same length with a smaller diameter

The circuit diagram shows a 4.0Ω resistor and an 8.0Ω resistor connected to a 6.0 V battery.What is the potential difference (p.d.) across the 4.0Ω resistor?

• 0.5 V

• 2.0 V

• 4.0 V

• 6.0 V

Diagram 1 shows two thin, uncharged strips of plastic. Diagram 2 shows the same strips after they have been rubbed with a dry cloth.

• A

• B

• C

• D