Question

In a Wheatstone’s bridge, if the galvanometer shows zero deflection, find the unknown resistance. Given P = 1000Ω Q = 10000 Ω and R = 20 Ω

Answer 1

There is the little mistake in the Question. Unknown Resistance is represented by the letter R which is already given in the Question. Variable Resistance which is not given, we need to find that only.


Given conditions ⇒

P = 1000 Ω
Q = 10000 Ω
R = 20 Ω

Now, we know the Formula,

 P/Q = R/S
∴ 1000/10000 = 20/S
∴ S = 20 × 10
∴ S = 200 Ω

Hence, the Variable Resistance is 200 Ω.


Hope it helps.