1. Tardigrade
  2. Question
  3. Physics
  4. 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 />

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

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
Question

NTA AbhyasNTA Abhyas 2022

Solution:

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 $AC$ and $AB$ will be equal to the ratio of corresponding resistances on other side.
Now, if the cross-sectional diameter of the wire $AB$ is doubled, the resistance of wire will get one-fourth.
But as the ratio of the resistances of wires $AC$ and $AB$ will remain same, the null point of the galvanometer will remain constant as $x$ .