Question

The resistance of each arm of the wheat stone bridge is 10 ohms. A resistance of 10 ohm is connected in series with a galvanometer then the equivalent resistance across the battery will be :

• A. 10 ohm
• B. 15 ohm
• C. 20 ohm
• D. 40 ohm

Answer 1

Answer: (A)

10 ohm

Answer 2

The correct option is(A): 10 ohm.
In this scenario, where P, Q, S, and R all have values of 10Ω, and considering that $\frac{Q}{P}=\frac{R}{S}$ = 1, we have a balanced Wheatstone bridge configuration. Consequently, there is no current flowing through the galvanometer. Since all the individual arm resistances are equal, the equivalent resistance of the bridge also remains at 10Ω.