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Question
How does the resistance of a metallic wire depend on its temperature? Explain with reason.
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Solution 1
With the increase in temperature of conductor, both the random motion of electrons and the amplitude of vibration of fixed positive ions increase. As a result, the number of collisions increases. Hence, the resistance of a conductor increases with the increase in its temperature. The resistance of filament of a bulb is more when it is glowing (i.e., when it is at a high temperature) as compared to when it is not glowing (i.e., when it is cold).
Solution 2
The resistance of a metallic wire increases with increase in its temperature.
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