Question

The circuit shown here is used to compare the e.m.f.'s of the cells $E_1$ and $E_2(E_1>E_2)$. When the galvanometer is connected to $E_1$, the null point is at $C$. When the galvanometer is connected to $E_2$, the null point will be

• A. to the left of $C$
• B. to the right of $C$
• C. at $C$ itself
• D. no where on $AB$

Answer 1

The correct option is A to the left of $C$

Since $E\propto l$. So, for $E_1>E_2$ we have $l_1>l_2$ and hence null point will be obtained at shorter length i.e., to the left of $C$.
Hence, the correct answer is (A).