In the potentiometer circuit shown in Fig. , the balance (null) point is at X. State with reason, where the balance point will be shifted when

Resistance $\mathrm{S}$ is increased, keeping $\mathrm{R}$ constant.

In the potentiometer circuit shown in Fig. , the balance (null) point is at X. State with reason, where the balance point will be shifted when

Cell $\mathrm{P}$ is replaced by another cell whose emf is lower than that of cell $\mathrm{Q}.$

A potentiometer wire has a length Land a resistance ${\mathrm{R}}_0$. It is connected to a battery and a resistance combination as shown. Obtain an expression for the potential drop per unit length of this potentiometer wire.

What is the maximum emf of a 'test cell' for which one can get a 'balance point' on this potentiometer wire ? What precaution should one take, while connecting this 'test cell' in the circuit?

The following circuit shows the use of potentiometer to measure the internal resistance of a cell:

When the key K is open, how does the balance point change, if the current from the driver cell decreases?

The following circuit shows the use of potentiometer to measure the internal resistance of a cell:

When the key $\mathrm{K}$ is closed, how does the balance point change if $\mathrm{R}$ is increased, keeping the current from the driver cell constant?

 A potentiometer wire of length $1 \mathrm{m}$ is connected to a driver cell of emf $3 \mathrm{V}$ as shown in Fig. 

When a cell of $1.5 \mathrm{V} \mathrm{emf}$ is used in the secondary circuit, the balance point is found to be $60 \mathrm{cm}$. On replacing this cell and using a cell of unknown emf, the balance point shifts to $80 \mathrm{cm}$.

Calculate unknown emf of the cell.

 A potentiometer wire of length $1 \mathrm{m}$ is connected to a driver cell of emf $3 \mathrm{V}$ as shown in Fig. 

When a cell of $1.5 \mathrm{V} \mathrm{emf}$ is used in the secondary circuit, the balance point is found to be $60 \mathrm{cm}$. On replacing this cell and using a cell of unknown emf, the balance point shifts to $80 \mathrm{cm}$.

Explain with reason, whether the circuit works, if the driver cell is replaced with a cell of emf $1 \mathrm{V}$.

 A potentiometer wire of length $1 \mathrm{m}$ is connected to a driver cell of emf $3 \mathrm{V}$ as shown in Fig. 

When a cell of $1.5 \mathrm{V} \mathrm{emf}$ is used in the secondary circuit, the balance point is found to be $60 \mathrm{cm}$. On replacing this cell and using a cell of unknown emf, the balance point shifts to $80 \mathrm{cm}$.

Does the high resistance $\mathrm{R}$, used in the secondary circuit affect the balance point? Justify your answer.

Figure shows the circuit diagram of a potentiometer for determining the emf $\text{'}\epsilon \text{'}$ of a cell of negligible internal resistance.

What is the purpose of using high resistance ${\mathrm{R}}_2$ ?