Wheatstone Bridge — Prelims Questions

In a Wheatstone bridge, the four arms have resistances $P=10,Omega$, $Q=20,Omega$, $R=15,Omega$, and $S=X,Omega$. If the bridge is balanced, what is the value of $X$?

In a meter bridge experiment, the null point is found at $40,\text{cm}$ from the left end when a resistance $R$ is placed in the left gap and a $12,Omega$ resistor in the right gap. What is the value of $R$?

In a Wheatstone bridge, if the battery and galvanometer are interchanged, what happens to the balanced condition?

A Wheatstone bridge has resistances $P=5,Omega$, $Q=10,Omega$, $R=10,Omega$, and $S=15,Omega$. A galvanometer with resistance $R_g = 5,Omega$ is connected across the bridge. If a $6,\text{V}$ battery is connected across the bridge, is the bridge balanced? If not, in which direction would current flow through the galvanometer (from B to D or D to B)?

In a meter bridge, the null point is found at $30,\text{cm}$ from the left end when a resistance $R_1$ is in the left gap and $R_2$ in the right gap. If $R_1$ and $R_2$ are interchanged, the null point shifts by:

Which of the following factors does NOT affect the balanced condition of a Wheatstone bridge?