For the circuit shown,with $R_1 = 1.0\,\Omega$,$R_2 = 2.0\,\Omega$,$E_1 = 2\,V$ and $E_2 = E_3 = 4\,V$,the potential difference between the points $a$ and $b$ is approximately (in $V$):

The resistance of each arm of the Wheatstone bridge is $10 \, \Omega$. A resistance of $10 \, \Omega$ is connected in series with a galvanometer. Then, the equivalent resistance across the battery will be:

The equivalent resistance between $P$ and $Q$ in the given figure is ............... $\Omega$.

Kirchhoff's first law,$i.e.$,$\Sigma i = 0$ at a junction,is based on the law of conservation of:

The figure shows a network of currents. The values of the currents are shown in the figure. What is the value of current $I$ in $A$?

Two batteries with e.m.f $12\ V$ and $13\ V$ are connected in parallel across a load resistor of $10\,\Omega$. The internal resistances of the two batteries are $1\,\Omega$ and $2\,\Omega$ respectively. The voltage across the load lies between