If the mass deposited in $30 \ s$ is $m$,what will be the $E.C.E$ of the copper voltameter?

$A$ light bulb of resistance $R = 16 \, \Omega$ is attached in series with an infinite resistor network with identical resistances $r$ as shown below. $A$ $10 \, V$ battery drives current in the circuit. Find the value of $r$ in $\Omega$ such that the bulb dissipates about $1 \, W$ of power.

$A$ cell of $e.m.f.$ $1.5\,V$ having a finite internal resistance is connected to a load resistance of $2\,\Omega$. For maximum power transfer,the internal resistance of the cell should be ............. $\Omega$.

As shown,the circuit is made of $8$ different resistors. It is found that when $R_1 = 4\,\,\Omega,$ the resistance between $A$ and $B$ is $2\,\,\Omega.$ Now replace $R_1$ by a $6\,\,\Omega$ resistor,what is the resistance between $A$ and $B$?

For the given circuit diagram,if the dissipated electrical power is $150 \text{ W}$,find the value of resistance $R$. (in $\Omega$)

In the given circuit,if $E_1 = 4\,V$,$R_1 = 2\,\Omega$,$E_2 = 6\,V$,$R_2 = 2\,\Omega$,and $R_3 = 4\,\Omega$,what is the value of current $i_1$ in $A$?