A straight wire is held perpendicular to a uniform magnetic field. A student doubles the current and reverses the field without changing its strength. Which describes the magnetic forces on the wire and on the magnet?
Both forces double in size and both reverse direction.
Both forces halve in size and neither reverses direction.
Both forces halve in size and both reverse direction.
Both forces double in size and neither reverses direction.
86 exam-style questions on Edexcel GCSE Physics 12.3 The motor effect, covering 12.3.1 The motor effect, 12.3.2 Fleming's left-hand rule, 12.3.3 Force on a conductor, and 12.3.4 Electric motors. Each one has a worked solution and a mark scheme showing where the marks go.