Physics Quiz on Electricity and Magnetism

A flexible electrical cable consists of a central conductor and outer insulation. Which pair of materials is suitable for the cable?

• A

• B

• C

• D

The diagram shows a battery connected to two resistors. Four students separately measure the electromotive force (e.m.f.) of the battery, the current in the resistors, and the potential difference (p.d.) across resistor R. Which row shows values with their correct units?

• A

• B

• C

• D

The table describes four different resistance wires. They are all made from the same metal. Which wire has the smallest resistance?

• A

• B

• C

• D

A student uses a length of wire as a resistor. He makes a second resistor from the same material. To be certain of making a second resistor of higher resistance, he should use a piece of wire that is _____

• longer and thicker.

• longer and thinner.

• shorter and thicker.

• shorter and thinner.

What is the unit of electrical power?

• ampere

• joule

• volt

• watt

The circuit shown contains a battery, a 6.0 Ω resistor and two meters X and Y. Which row shows possible values for the readings on the meters?

• A

• B

• C

• D

The switch is open, and the ammeter reads 2.0 A.

The switch is now closed, and the ammeter reads the total current in both resistors. What is the ammeter reading with the switch closed?

• 1.2 A

• 3.0 A

• 4.0 A

• 5.0 A

Why are high voltages used for the transmission of electrical energy?

• Fear of high voltages stops people from interfering with the cables.

• Heat loss in the cables is smaller than if high voltages are used.

• High voltages increase the current in the cables.

• High voltages produce large magnetic fields, so less insulation is needed.

What is the reading on the voltmeter?

• 2.4 V

• 3.6 V

• 6.0 V

• 9.6 V

Which group contains only good electrical conductors?

• air, carbon (graphite), plastic

• air, gold, mercury

• carbon (graphite), copper, mercury

• copper, gold, plastic