Question

{"1":{"data":"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.","imageType":"-1","image":"-1"},"2":{"data":"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.","imageType":"-1","image":"-1"}}

Answer 1

With increase in temperature, the value of unknown resistance will increase.
In balanced Wheat stone bridge condition,
$ \, \, \, \, \, \, \, \, \, \, \, \, \, \, \frac{R}{X} = \frac{l_1}{l_2}$
Here, R = value of standard resistance.
$ \, \, \, \, $X = value of unknown resistance.
To take null point at same point or $\frac{l_1}{l_2}$ to remain unchanged, $\frac{R}{X}\, $should also remain unchanged
Therefore, if X is increasing R, should also increase.
$\therefore $ Correct option is (d).