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COMEDK2012PhysicsCurrent Electricity

Wires made of iron and silicon are cooled from 50^ C to 30^ C , then

Options

  1. Aresistance of both wires decreases
  2. Bresistance of both wires increases
  3. Cresistance of iron increases and that of silicon decreases
  4. Dresistance of iron decreases and that of silicon increases

Correct answer

D. resistance of iron decreases and that of silicon increases

Step-by-step solution

The conductors have positive temperature coefficient, while semiconductors have negative temperature coefficient. So, when iron and silicon wires are cooled from 50^ C to 30^ C , the resistance of iron decreases, while that of silicon increases.

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