In the given circuit, the cells have zero internal resistance. The currents (in Amperes) passing through resistance $R_1$ and $R_2$ respectively, are

$A$ battery has an $e.m.f.$ of $4\, V$ and an internal resistance $r$. When this battery is connected to an external resistance of $2\, \Omega$,a current of $1\, A$ flows in the circuit. How much current will flow if the terminals of the battery are connected directly?

Which arrangement of four identical resistances should be used to draw maximum energy from a cell of voltage $V$?

In the given electrical circuit,the potential difference between points $P$ and $Q$ is ........... $V$.

Two resistances of $400 \Omega$ and $800 \Omega$ are connected in series with a $6 \text{ V}$ battery of negligible internal resistance. $A$ voltmeter of resistance $10000 \Omega$ is used to measure the potential difference across the $400 \Omega$ resistor. The error in the measurement of potential difference in volts is approximately:

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 $A$?