In a meter bridge, the wire of length 1 m has a non-uniform cross-section such that the variation \[\frac{dR}{dl}\]of its resistance R with length l is \[\frac{dR}{dl}\propto \frac{1}{\sqrt{l}}.\] Two equal resistances are connected as shown in the figure. The galvanometer has zero deflection when the jockey is at point P. What is the length AP? [JEE Main 12-Jan-2019 Morning] |
A) 0.35 m
B) 0.2 m
C) 0.25 m
D) 0.3 m
Correct Answer: C
Solution :
[c] Let AP be the length |
Taking integration on both the sides |
Balancing point will divide the resistance in equal part. So, l will be correspond to . |
or |
You need to login to perform this action.
You will be redirected in
3 sec