In this given circuit, no current is passing through the galvanometer. If the cross-sectional diameter of the wire AB is doubled, then for null point of galvanometer the value of AC would

Question

In this given circuit, no current is passing through the galvanometer. If the cross-sectional diameter of the wire AB is doubled, then for null point of galvanometer the value of AC would <img class="img-fluid question-image" alt="Question" src="https://cdn.tardigrade.in/q/nta/p-uyaihrzyhmwyd7dt.jpg" /> (A) (x/4) (B) 4x (C) 2x (D) x

Tardigrade Admin · Accepted Answer

As there is no current passing through the galvanometer, the circuit is in a balanced Wheatstone bridge condition.
The ratio of resistances and therefore ratio of lengths of

A C

and

A B

will be equal to the ratio of corresponding resistances on other side.
Now, if the cross-sectional diameter of the wire

A B

is doubled, the resistance of wire will get one-fourth.
But as the ratio of the resistances of wires

A C

and

A B

will remain same, the null point of the galvanometer will remain constant as

x

.

Q. In this given circuit, no current is passing through the galvanometer. If the cross-sectional diameter of the wire $A B$ is doubled, then for null point of galvanometer the value of $A C$ would

$\frac{x}{4}$

$4 x$

$2 x$

$x$

Q. In this given circuit, no current is passing through the galvanometer. If the cross-sectional diameter of the wire AB is doubled, then for null point of galvanometer the value of AC would

4x​

4x

2x

x

Q. In this given circuit, no current is passing through the galvanometer. If the cross-sectional diameter of the wire $A B$ is doubled, then for null point of galvanometer the value of $A C$ would

$\frac{x}{4}$

$4 x$

$2 x$

$x$