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NEET 1995 (AIPMT) · Electrical Power & Heating Effect

Electrical Power & Heating Effect question from NEET 1995 (AIPMT)

Q99NEET 1995 · AIPMTEasy

Electrical Power & Heating Effect

A heating coil is labelled 100 W, 220 V. The coil is cut in half and the two pieces are joined in parallel to the same source. The energy now liberated per second is

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Answer: (b)

  1. Each half has resistance R/2R/2; two halves in parallel give R/4R/4.
  2. At the same voltage P=V2/RP = V^2/R, so P′=4P=4×100P' = 4P = 4 \times 100.
  3. So the answer is (b) 400 W400\text{ W}.
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