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A uniform wire connected across a supply dissipates power H. If the wire is cut into n equal parts and all parts are connected in parallel across the same supply, the total power dissipated is

1. H/n²
2. n² H
3. n H
4. H/n

Correct answer: n² H

Solution

Original R gives H = V²/R. Cutting into n parts (each R/n) and paralleling gives equivalent R/n², so power = V²/(R/n²) = n² V²/R = n² H.

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