The metre bridge shown is in a balanced position with $\frac{P}{Q}=\frac{l_1}{l_2}$. If we now interchange the position of the galvanometer and the cell, will the bridge work? If yes, what will be the balanced condition?

According to the principle of conjugate branches of a Wheatstone bridge, the balance condition remains unchanged if the positions of the battery and the galvanometer are interchanged.Initially, balance condition is $\frac{P}{Q}=\frac{l_1}{l_2}$.After interchanging, the bridge still works and the balance condition remains $\frac{P}{Q}=\frac{l_1}{l_2}$.