A straight copper wire carrying an electric current is placed in a uniform magnetic field, causing a magnetic force to act on the wire.
Which of the following statements is correct?
The force is strongest when the wire is aligned parallel to the magnetic field.
If the direction of the magnetic field is reversed while the direction of the current remains unchanged, the direction of the force is reversed.
Reversing both the direction of the current and the direction of the magnetic field reverses the direction of the force.
The force acts in a direction parallel to the current flowing through the wire.
275 exam-style questions on CIE IGCSE Physics 4.5 Electromagnetic effects, covering 4.5.1a Electromagnetic induction, 4.5.1b Direction of an induced e.m.f., 4.5.2 The a.c. generator, 4.5.3a Magnetic effect of a current and its applications, 4.5.3b Strength and direction of the field around wires and solenoids, 4.5.4a Force on a current-carrying conductor, 4.5.4b Force on beams of charged particles, 4.5.5 The d.c. motor, 4.5.6a Construction and operation of a transformer, 4.5.6b Turns ratio and current in a transformer, and 4.5.6c High-voltage transmission of electricity. Each one has a worked solution and a mark scheme showing where the marks go.