A straight wire carrying an electric current is positioned in a magnetic field, experiencing a magnetic force. Which of the following actions will result in the direction of this force being reversed?
Reversing both the current direction and the magnetic field direction
Reversing the magnetic field direction while keeping the current direction unchanged
Increasing the current magnitude while keeping the magnetic field direction unchanged
Decreasing the strength of the magnetic field while keeping the current direction unchanged
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.