A) independent of temperature
B) increases as the temperature rises
C) decreases as the temperature rises
D) increases or decreases as temperature rises depending upon the metal.
Correct Answer: B
Solution :
The resistance of a metallic wire at temperature \[t{}^\circ C\]is given by \[{{R}_{t}}={{R}_{0}}\left( 1+\alpha t \right)\], where \[\alpha \] is the temperature coefficient of resistance and \[{{R}_{0}}\]is the resistance of a wire at \[0{}^\circ C\]. For meals, \[\alpha \] is positive. Hence, resistance of a wire increases with increase in temperature. Also, from Ohm's law \[\frac{V}{I}=R\] Hence on increasing the temperature the ratio \[\frac{V}{I}\]increases.
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