D. C. Pandey Solutions for Chapter: Current Electricity, Exercise 5: [ Level 2 ]

A cell of constant emf first connected to resistance $R_1$ and then connected to resistance $R_2$. If power delivered in both cases is same then the internal resistance of the cell is:

In the diagram shown, the reading of voltmeter is $20 \mathrm{V}$ and that of ammeter is $4 \mathrm{A}$. The value of $R$ should be (consider given ammeter and voltmeter are not ideal)

As the switch $S$ is closed in the circuit shown in figure, the current passing through it is:

Current through wire $XY$ of circuit shown is

The current in resistance $R_3$ in the given circuit is:

Two batteries of emf ${\epsilon }_1$ and ${\epsilon }_2\left({\epsilon }_2>{\epsilon }_1\right)$ and internal resistances $r_1$ and $r_2$ respectively are connected in parallel as shown in figure.

A resistance $R$ is to be measured using a meter bridge, student chooses the standard resistance $S$ to be $100 \mathrm{\Omega }$. He finds the null point at $l_1=2.9 \mathrm{cm}$. He is told to attempt to improve the accuracy.

Which of the following is a useful way?

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