A wire of length 5.0 cm carries a current of 400 mA. The wire is at right angles to a magnetic field of magnetic flux density 0.25 T0.25\ \text{T}0.25 T.
What is the force on the wire?
0.50 N0.50\ \text{N}0.50 N
5.0×10−3 N5.0 \times 10^{-3}\ \text{N}5.0×10−3 N
5.0 N5.0\ \text{N}5.0 N
500 N500\ \text{N}500 N
48 exam-style questions on OCR GCSE Physics 4.2 Uses of magnetism, covering 4.2.1 The motor effect, 4.2.2 Fleming's left-hand rule, 4.2.3 The force on a current-carrying conductor, 4.2.4 The electric motor, 4.2.5 Electromagnetic induction, 4.2.6 Alternators and dynamos, 4.2.7 How transformers work, 4.2.8 Transformer turns ratio, 4.2.9 Potential differences and turns in transformers, and 4.2.10 Microphones, loudspeakers and headphones. Each one has a worked solution and a mark scheme showing where the marks go.