Statement-1 : In a Meter Bridge experiment, null point for an unknown resistance is measured. Now, the unknown resistance is put inside an enclosure maintained at a higher temperature. The null point can be obtained at the same point as before by decreasing the value of the standard resistance.
Statement-2 : Resistance of metal increases with increase in temperature.

Options

A. Statement-1 is true, Statement-2 is True, Statement-2 is a correct explanation for Statement-1
B. Statement -1 is True, Statement-2 is True, Statement -2 is NOT a correct explanation for Statement-1.
C. Statement-1 is True, Statement-2 is False.
D. Statement-1 is False, Statement-2 is True.

Answer

D

Explanation

(d) When the temperature of metal increases, its resistance
increases.
Therefore statement-2 is correct.

For a meter bridge when null point N is obtained we get
`X/l = S/(100-l)`
When the unknown resistance is put inside an
enclosure, maintained at a high temperature, then X
increases. To maintain the ratio of null point l should
also increase. But if we want to keep the null point at
the initial position (i.e., if we want no change in the
value of l) there to maintain the ratio, S should be
increased.
Therefore statement-1 is false.