Physics · Series and parallel combinations of resistors, temperature dependence of resistance
Assertion The temperature coefficient of resistance is always positive. Reason O
Assertion The temperature coefficient of resistance is always positive. Reason On increasing the temperature the resistance of metals and alloys increase.
- A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
- B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
- C. Assertion is correct but Reason is incorrect
- D. Assertion is incorrect but Reason is correct
Step-by-step solution
The assertion is false because the temperature coefficient of resistance is not always positive; it is negative for semiconductors and insulators, and even some metals at very low temperatures can exhibit negative coefficients. The reason is true for metals and alloys, as their resistance increases with temperature, but it does not justify the universal claim in the assertion.
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