A wire is perpendicular to a uniform magnetic field. A student uses the total wire length of 0.60 m to calculate B B\,B from the measured force and current. Only 0.12 m of the wire is inside the field. Which describes the student’s calculated value of BBB?
Five times the correct value, because the length used is too large.
One-fifth of the correct value, because the length used is too large.
One-fifth of the correct value, because the length used is too small.
Five times the correct value, because the length used is too small.
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.