Question

In the adjoining circuit, the battery $X$ in ohm is

• A. 10
• B. 100
• C. 500
• D. 200

Answer 1

Answer: (B)

100

Answer 2

For no current through galvanometer, we have

$\left( \frac { E _ { 1 } } { 500 + X } \right) X = E$ ⇒ $\left( \frac { 12 } { 500 + X } \right) X = 2$ ⇒ X = 100 Ω