GENERATORS
3 marks · NormalA single straight wire is pulled at a speed of 0.5 m/s across a uniform magnetic field of strength 0.8 T. The length of the wire in the field is 20 cm. Calculate the maximum possible voltage induced across the ends of the wire.
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0.08 V (±0.01)
Common mistakes: Using wrong units for length; Using wrong equation
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Marking points
M1 · 1 mark · Substitutes correctly into E = B l v
A1 · 1 mark · Uses correct units for length (converts 20 cm to 0.20 m)
A2 · 1 mark · Arrives at final answer: 0.08 V (accept 0.08 V, 0.080 V, 80 mV).
Worked solution
Given: B = 0.8 T, l = 20 cm = 0.20 m, v = 0.5 m/s.