In the given circuit,when the switch $S$ is closed,what is the current in amperes flowing through it?

The resistance between points $A$ and $B$ is

$A$ cell of constant $e.m.f.$ is connected first to an external resistance $R_1$ and then to an external resistance $R_2$. If the power consumed in both cases is the same,what is the internal resistance of the cell?

$A$ current source drives a current in a coil of resistance $R_1$ for a time $t$. The same source drives current in another coil of resistance $R_2$ for the same time. If the heat generated is the same,find the internal resistance of the source.

In the circuit shown below,the resistances are given (in $\Omega$) and the battery is assumed ideal with an electromotive force (emf) equal to $3.0 \, V$. The resistor that dissipates the most power is

In the circuit shown in the figure,the resistance of the voltmeter is $6 \, k\Omega$. The voltmeter reading will be ................. $V$.