B M Sharma Solutions for Chapter: Electrical Measuring Instruments, Exercise 3: DPP

A cell of internal resistance $1.5 \mathrm{\Omega }$ and of emf $1.5 \mathrm{V}$ balances at $500 \mathrm{cm}$ on a potentiometer wire. If a wire of $15 \mathrm{\Omega }$ is connected between the balance point and the cell, then the balance point will shift

For comparing the emf of two cells with a potentiometer, a standard cell is used to develop a potential gradient along the wires. Which of the following possibilities would make the experiment unsuccessful?

The circuit shown here is used to compare the emf of two cells $E_1$ and $E_2 \left(E_1>E_2\right)$. The null point is at $C$, when the galvanometer is connected to $E_1$. When the galvanometer is connected to $E_2,$ the null point will be

A resistance of $4 \mathrm{\Omega }$, a wire of length $5$ $\mathrm{m}$ and a resistance $5 \mathrm{\Omega }$ are joined in series and connected to a cell of emf $10 \mathrm{V}$ and internal resistance $1 \mathrm{\Omega }$. A parallel combination of two identical cells is balanced across $300 \mathrm{cm}$ of the wire. The emf $E$ of each cell is

The length of a wire of a potentiometer is $100 \mathrm{cm}$ and the emf of its standard cell is $E$ volt. It is employed to measure the emf of a battery whose internal resistance is $0.5 \mathrm{\Omega }$. If the balance point is obtained at $l=30 \mathrm{cm}$ from the positive end, the emf of the battery is

Potentiometer wire of length $1 \mathrm{m}$ is connected in series with$490 \mathrm{\Omega }$ resistance and  $2 \mathrm{V}$ battery. If $0.2 \mathrm{mV} {\mathrm{cm}}^{-1}$ is the potential gradient, then the resistance of the potentiometer wire is
 

The figure shows a simple potentiometer circuit for measuring a small emf produced by a thermocouple. The meter wire $PQ$ has a resistance $5 \mathrm{\Omega }$ and the driver cell has an emf of $2 \mathrm{V}$. If a balanced point is obtained $0.600 \mathrm{m}$ along $PQ$ when measuring an emf of $6.00 \mathrm{mV},$ what is the value of resistance $R$?

Two cells of emfs approximately $5 \mathrm{V}$ and $10 \mathrm{V}$ are to be accurately compared using a potentiometer of length $400 \mathrm{cm}$