$A$ copper voltameter is connected to a $12 \, V$ source,and $2 \, g$ of copper is deposited in $30 \, min$. If this cell is connected to a $6 \, V$ source,how much copper (in $g$) will be deposited in $45 \, min$?

The actual value of resistance $R$,shown in the figure is $30\,\Omega$. This is measured in an experiment as shown using the standard formula $R_{measured} = \frac{V}{I}$,where $V$ and $I$ are the readings of the voltmeter and ammeter,respectively. If the measured value of $R$ is $5\%$ less than the actual value,then the internal resistance of the voltmeter is ................. $\Omega$.

The thermo $e.m.f.$ of a thermocouple is $25\,\mu V/^{\circ}C$ at room temperature. $A$ galvanometer of $40\,\Omega$ resistance, capable of detecting current as low as $10^{-5}\,A$, is connected with the thermocouple. The smallest temperature difference that can be detected by this system is ................ $^{\circ}C$.

If a $30\, V, 90\, W$ bulb is to be operated on a $120\, V$ line,what resistance in ohms should be connected in series with the bulb?

In the given figure,the equivalent resistance between the points $A$ and $B$ is ............ $\Omega$.

Find the current passing through the battery immediately after the key $(K)$ is closed. It is given that initially all the capacitors are uncharged. (Given that $E = 5 \, V$, $R = 6 \, \Omega$) (in $A$)