A motor contains a rectangular coil with 32 turns. On one side of the coil, a 45 mm section of every turn lies at right angles to a uniform magnetic field.
A current of 2.5 A flows through the coil. The combined magnetic force on the 32 sections is 1.08 N.
Calculate the magnetic flux density.
The current in the coil decreases to 1.8 A. The magnetic flux density and the number of turns remain unchanged.
Calculate the new combined magnetic force on the sections.
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.