Question 492: Current Electricity

Question

The length of a potentiometer wire is ' $L$ '. A cell of e.m.f. ' $E$ ' is balanced at a length $\frac{L}{4}$ from the positive end of the wire. If the length of the original wire is increased by $\frac{\mathrm{L}}{3}$, then using the same cell null point is obtained at

Accepted Answer

If the length of potentiometer is increased by $\frac{L}{3}$ the balancing length will also increase by the same proportion. Therefore the balancing length will increase from $\frac{\mathrm{L}}{4}$ to $\left(\frac{1}{3} 	imes \frac{\mathrm{L}}{4}ight)$.
$$ \Rightarrow \frac{\mathrm{L}}{4}+\frac{\mathrm{L}}{12}=\frac{4 \mathrm{~L}}{12}=\frac{\mathrm{L}}{3} $$

Answer

$\frac{\mathrm{L}}{4}$

Answer

$\frac{\mathrm{L}}{3}$

Answer

$\frac{\mathrm{L}}{2}$

Answer

$\frac{3 L}{4}$

Current Electricity

The length of a potentiometer wire is ' L '. A cell of e.m.f. ' E ' is balanced at a length \frac{L}{4} from the positive end of the wire. If the length of the original wire is increased by \frac{\mathrm{L}}{3}, then using the same cell null point is obtained at

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