A wire 0.2 m long carries 2 A at right angles to a magnetic field of 0.5 T. What force acts on it?
Answer and explanation
Correct answer: A. 0.2 N
- Step 1: F = BIL sin θ, with sin 90° = 1. Step 2. F = 0.5 × 2 × 0.2 = 0.2 N. Answer: 0.2 N. Why not the others: 1 N is what you get if you forget the length. 0.8 N is what you get if you divide by B. 2 N is what you get if you misplace a power of ten.
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