Question bank: Unit 2 — Electricity and Magnetism

A current of 3 A flows in a wire for 20 s. The charge that passes a cross-section is:

A charge of 240 C passes a point in 2 minutes. The current is:

The volt is equivalent to:

Work of 60 J is done to move 5 C between two points. The potential difference is:

To measure the current in a lamp, an ammeter must be connected:

A voltmeter measuring the voltage across a lamp is connected:

By convention, the electric current outside the source flows from:

Which of the following is needed for a current to flow in a wire?

The potential difference between the terminals of a battery in a working circuit is slightly less than its emf because of:

Four identical 1.5 V cells are connected in series. The emf is:

The same four 1.5 V cells connected in parallel give an emf of:

Which statement about connecting cells in parallel is correct?

Increasing the length of a wire of the same material and thickness:

Two wires of the same metal and the same length have cross-sectional areas A and 2A. The thicker wire has:

The filament of a bulb glows while the copper connecting wires do not, because the filament:

A rheostat is used to:

The unit of electric resistance is the:

Ohm's law states that, at constant temperature, the current through a conductor is:

The potential difference across a resistor is 24 V and the current is 3 A. Its resistance is:

The current through a 4 Ω resistor connected to a 12 V battery is:

In an experiment to verify Ohm's law, the factor that must be kept constant is:

If the potential difference across a fixed resistor is doubled, the current becomes:

Four identical 5 Ω resistors are connected in series. The equivalent resistance is:

Three identical 9 Ω resistors are connected in parallel. The equivalent resistance is:

The equivalent resistance of identical resistors connected in parallel is:

Three identical resistors in parallel have an equivalent resistance of 2 Ω. If they are connected in series, the equivalent resistance is:

Household appliances are connected in parallel so that:

Resistors in series have the same:

The unit watt is equivalent to:

One kilowatt-hour equals:

A 100 W lamp works for 5 hours. The energy consumed is:

A 2 kW heater runs for 3 hours. If a kW·h costs 1.5 pounds, the cost is:

Which of these is a common unit for measuring household electrical energy bills?

Which action is unsafe?

Oersted discovered that an electric current flowing in a wire:

Soft iron is used as the core of an electromagnet because it:

Which change does NOT increase the strength of an electromagnet?

An electric motor converts:

The principle of operation of an electric generator is the: