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A compass is held close to a wire while a current flows through the wire. What happens to the compass needle?
AIt stops moving
BIt falls apart
CIt is deflected
DIt becomes hot
Answer & Solution
Correct answer: C. It is deflected
1. A compass needle lines itself up along magnetic field lines.
2. Held near a wire carrying a current, the needle on the compass is deflected.
3. The deflection is evidence that a magnetic field exists near the wire.
4. Switching the current off makes the needle swing back to its original direction.
_Source: Siyavula Physical Sciences Grade 11 (Everything Science, CC BY 4.0), Chapter 10: Electromagnetism_
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