In the circuit shown, the brightness of the lamp can be altered by changing the resistance of the variable resistor, R.

1.   ?    the current flowing in the circuit.
2.   ?    the electromotive force (e.m.f.) of the battery.
3.   ?    the resistance of the bulb.
4.   ?    the temperature of the battery.

A wire of length 1.0 m has a resistance of 2.0 ohms.
When connected to a cell, the current in the wire is 3.0 A.

1.   ?    resistance: 1.0 ohm ; current: 1.5 A
2.   ?    resistance: 1.0 ohm ; current: 3.0 A
3.   ?    resistance: 4.0 ohm ; current: 1.5 A
4.   ?    resistance: 4.0 ohm ; current: 3.0 A

The potential difference between the ends of a conductor is 12 V.

How much electrical energy is converted to other forms of energy in the conductor when 100 C of charge flows through it?

1.   ?    0.12 J
2.   ?    8.3 J
3.   ?    88 J
4.   ?    1 200 J

A piece of wire 0.5 m long has an area of cross-section of 1 mm².

Which piece of wire of the same material has twice the resistance?

1.   ?    length: 0.5 m ; area: 2.0 mm²
2.   ?    length: 0.5 m ; area: 0.5 mm²
3.   ?    length: 1.0 m ; area: 2.0 mm²
4.   ?    length: 1.0 m ; area: 0.5 mm²

Which of the following may be given as joules / coulomb?

1.   ?    amps
2.   ?    ohms
3.   ?    volts
4.   ?    watts

Which of the following describes the e.m.f of a cell?

1.   ?    The difference in energy between that needed to drive unit charge through the load resistors and through the cell.
2.   ?    The energy used to drive unit charge through all the load resistors in the circuit.
3.   ?    The energy used to drive charge through the resistance of the cell.
4.   ?    The total energy used to drive unit charge round the complete circuit.

A milliammeter shows a reading of 30 mA.

How much electrical charge flows through the milliammeter in 10 seconds?

1.   ?    0.3 C
2.   ?    3.0 C
3.   ?    30 C
4.   ?    300 C

Which of the following quantities has the same unit as electromotive force?

1.   ?    Charge
2.   ?    Current
3.   ?    Potential Difference
4.   ?    Power

Identical cells are used in both of the circuits shown.

1.   ?    1 ohm
2.   ?    1.5 ohm
3.   ?    5 ohm
4.   ?    6 ohm

An electric current in a metal wire involves the movement of ................

1.   ?    atoms
2.   ?    electrons
3.   ?    molecules
4.   ?    protons

A 240 kV electrical transmission system carries a power of 12 MW.

What is the current in the wires?

1.   ?    50 000 A
2.   ?    20 000 A
3.   ?    50 A
4.   ?    20 A

Which graph best represents how current I varies with voltage V in a component in which the resistance decreases as the current increases?

1.   ?    A
2.   ?    B
3.   ?    C
4.   ?    D

Which circuit would be suitable for measuring the resistance of a lamp?

1.   ?    A
2.   ?    B
3.   ?    C
4.   ?    D

A 4 ohm resistor is connected in series with an ammeter and a 6V battery, as shown.

1.   ?    0.67 A
2.   ?    1.5 A
3.   ?    2 A
4.   ?    24 A

The diagram shows a battery with an electromotive force of 6 V in a circuit.

1.   ?    0.2 J
2.   ?    5 J
3.   ?    24 J
4.   ?    180 J