Question
The resistances in the two arms of the meter bridge are 5 ohm and R ohm, respectively. When the resistance R is shunted with an equal resistance, the new balance point is at 1.6 l1. The resistance R is,
-
10 ohm
-
15 ohm
-
20 ohm
-
25 ohm
Solution
B.
15 ohm
Case 1:
... (i)
Now, by shunting resistance R by an equal resistance R, new resistance in that arm become R/2
So, 
... (ii)
From equations (i) and (ii),
160 - 1.6 l1 = 200 - 3.2 l1
1.6 l1 = 40
From equation (i),
