A wheatstone bridge is used to determine the value of unknown resistance $X$ by adjusting the variab

Question

A wheatstone bridge is used to determine the value of unknown resistance $X$ by adjusting the variable resistance $Y$ as shown in the figure. For the most precise measurement of $X$, the resistances $P$ and $Q$\

Professor PC Thomas Classes · Answer

(b) : For a balanced wheatstone bridge, current through a galvanometer is zero.\ $	herefore \frac{P}{Q}=\frac{X}{Y}$\ Here resistances $P$ and $Q$ should be approximately equal and small, as it decreases error in experiment.\