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The base of an electric iron is brightly polished mainly

  • A.To make it smooth and frictionless
  • B.To make it rust-proof
  • C.To reduce heat loss by radiation
  • D.To make it more durable

Answer: C

To reduce heat loss by radiation.

A polished surface has low emissivity, and by the Stefan-Boltzmann law the rate of radiation is \(E = e\sigma AT^4\). Keeping \(e\) small means the heat goes into the cloth rather than radiating away into the room.

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