NEET Physics Current Electricity Potentiometer MCQs

A potentiometer wire of length 100 cm has a resistance of 10 Ω. It is connected in series with a resistance box and a 2V cell of negligible internal resistance. If a cell of emf $E_1$ is balanced against a length of 40 cm and another cell of emf $E_2$ is balanced against a length of 60 cm when the resistance in the box is 10 Ω and 5 Ω respectively, the ratio $\frac{E_1}{E_2}$ is:

Two potentiometers, P1 and P2, have identical wires and driver cells. However, P1 uses a rheostat with a higher resistance range than P2. Which potentiometer will offer greater sensitivity in balancing a given cell?

A potentiometer wire AB is 100 cm long and has a total resistance of 10Ω. It is connected to a driver cell of emf E and internal resistance r. When a cell of emf $E_1$ is balanced against a length of $l_1$, the current through the potentiometer wire is $i_1$. When the cell $E_1$ is shunted by a resistance of 10Ω and balanced against a length $l_2$, the current through the potentiometer wire is $i_2$. Which of the following is true?

A potentiometer wire of length L and resistance R is connected to a driver cell of negligible internal resistance and emf E. A cell of emf E/2 is balanced at a length L/2. If the length of the potentiometer wire is doubled, at what length will the same cell be balanced?

In a potentiometer experiment, the balancing length for a cell is found to be $l$. If the driver cell is replaced by another cell of double the emf, what will be the new balancing length, assuming all other parameters remain constant?

A potentiometer is being used to compare two cells of emfs $E_1$ and $E_2$. The balancing lengths are found to be $l_1$ and $l_2$ respectively. If a resistance R is connected across $E_2$, its balancing length changes to $l_3$. Which of the following relations must hold true?

A potentiometer wire of length 1 m has a resistance of 10 Ω. A cell of emf 2 V and negligible internal resistance is connected to the wire. What is the potential gradient across the wire?

The potential gradient along the length of a uniform wire is 10 V/m. If the length of the wire is 0.1 m, what is the potential difference across it?

Which of the following is the principle behind the working of a potentiometer?

In a potentiometer, the null point is obtained at a length of 40 cm when the cell in the secondary circuit has an emf of 1.5 V. If the length of the potentiometer wire is 1 m, what is the potential gradient?