In an electroplating experiment,a current of $4 \ A$ is passed for $2 \ min$ to deposit a mass $m$ of silver. If a current of $6 \ A$ is passed for $40 \ s$,the mass of silver deposited is:

$A$ galvanometer $(G)$ of $2 \ \Omega$ resistance is connected in the given circuit. The ratio of charge in $C_1$ $(4 \ \mu F)$ and $C_2$ $(6 \ \mu F)$ is:

The terminal voltage $V$ across a battery of $emf$ $E$ and internal resistance $r$ can be:

When an electric heater is switched on, the current flowing through it $(I)$ is plotted against time $(t)$. Taking into account the variation of resistance with temperature, which of the following best represents the resulting curve?

If a battery of voltage $V$ is connected across terminals $I$ of the black box shown in the figure,an ideal voltmeter connected to terminals $II$ gives a reading of $V/2$. While if the battery is connected to terminals $II$,a voltmeter across terminals $I$ reads $V$. The black box may contain:

Two wires with resistances $R$ and $2R$ are connected in parallel. The ratio of heat generated in $2R$ and $R$ is: