The internal resistances of two cells shown in the figure are $0.1\,\Omega$ and $0.3\,\Omega$. If $R = 0.2\,\Omega$,find the potential difference across the cells.

The equivalent resistance between the points $A$ and $B$ will be (each resistance is $15 \Omega$): (in $\Omega$)

$A$ $12\, V$ lead accumulator is being charged using a $24\, V$ supply with an external resistance of $2\,\Omega$. The internal resistance of the accumulator is $1\,\Omega$. Find the time in which it will store $360\, Wh$ of energy.

In the given circuit,the voltmeter records $5 \, V$. The resistance of the voltmeter in $ohms$ is

Given below are two statements:
Statement $I:$ The equivalent resistance of resistors in a series combination is smaller than the least resistance used in the combination.
Statement $II:$ The resistivity of the material is independent of temperature.
In the light of the above statements,choose the correct answer from the options given below:

$A$ wire of uniform resistance $\lambda \ \Omega/m$ is bent into a circle of radius $r$. Two radial wires, each of length $r$, are connected from the center $O$ to points $A$ and $B$ on the circumference, where the angle $\angle AOB = 90^\circ$. The equivalent resistance between points $A$ and $B$ is . . . . . . $\Omega$.