Electricity and magnetism

A 12 V battery is connected across a 4 ohm resistor. What current flows?

• 1 0.33 A
• 2 3 A
• 3 8 A
• 4 48 A

Resistors of 2, 3 and 5 ohms are connected in series. What is the total resistance?

• 1 0.97 ohm
• 2 3.3 ohm
• 3 10 ohm
• 4 30 ohm

A 6 ohm and a 3 ohm resistor are connected in parallel. What is the equivalent resistance?

• 1 2 ohm
• 2 4.5 ohm
• 3 9 ohm
• 4 18 ohm

An appliance on 220 V draws 2 A. What is its power?

• 1 110 W
• 2 222 W
• 3 440 W
• 4 880 W

The SI unit of capacitance is the:

• 1 Henry
• 2 Farad
• 3 Tesla
• 4 Weber

The magnetic force on a moving charge is always:

• 1 Parallel to its velocity
• 2 Perpendicular to its velocity
• 3 Opposite to its velocity
• 4 Zero

A step-up transformer has:

• 1 More turns in the primary coil
• 2 More turns in the secondary coil
• 3 Equal turns in both coils
• 4 Only one coil

Faraday's law of induction states that the induced emf is proportional to:

• 1 The magnetic flux
• 2 The rate of change of magnetic flux
• 3 The resistance of the coil
• 4 The charge on the coil

How much electrical energy does a 2 kW heater use in 3 hours?

• 1 1.5 kWh
• 2 5 kWh
• 3 6 kWh
• 4 23 kWh

Lenz's law is a consequence of the conservation of:

• 1 Mass
• 2 Charge
• 3 Energy
• 4 Momentum