Question 105: Current Electricity

Question

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.
and
STATEMENT - 2
Resistance of a metal increases with increase in temperature.

Accepted Answer

When the temperature of a metal increases, its resistance will increase.
Therefore statement-2 is correct.
For meter bridge, when null point N is obtained, we get
$${X \over l} = {R \over {100 - l}}$$
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 to change the value of $$l$$) to maintain the ratio, R should be increased.
Therefore, statement - 1 is false.

Answer

Statement - 1 is True, Statement - 2 is True; Statement - 2 is a correct explanation for Statement - 1

Answer

Statement - 1 is True, Statement - 2 is True; Statement - 2 is NOT a correct explanation for Statement - 1

Answer

Statement - 1 is True, Statement - 2 is False

Answer

Statement - 1 is False, Statement - 2 is True

Current Electricity

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