The terminal potential difference of a cell is greater than its $e.m.f.$ when it is

The internal resistance of a primary cell is $4\,\Omega$. It generates a current of $0.2\,A$ in an external resistance of $21\,\Omega$. The rate at which chemical energy is consumed in providing the current is .............. $J/s$.

Electromotive force is the force,which is able to maintain a constant

When two identical batteries of internal resistance $1 \Omega$ each are connected in series across a resistor $R$,the rate of heat produced in $R$ is $P_1$. When the same batteries are connected in parallel across $R$,the rate of heat produced is $P_2$. If $P_1 = 2.25 P_2$,then the value of $R$ is (in $Omega$)

$A$ galvanometer is connected in series with an unknown resistor $R$ and two identical batteries of $1.5\, V$ each. When the batteries are connected in series,the galvanometer shows a current of $1\, A$. When the batteries are connected in parallel,it shows a current of $0.6\, A$. The internal resistance of each battery is: