The two bulbs, one of $60 \mathrm{W}$ and other $200 \mathrm{W}$ are connected in series to a $200 \mathrm{V}$ line, then,

$15$ cells each of emf $2$ volt are connected in series but $2$ of them are connected wrongly. Calculate the emf of the combination.

In the given circuit diagram, identify the objects marked as $1, 2, 3$.

How can a continuous flow of current be obtained? What are the sources of energy and name of the devices required for continuous flow of current?

In a meter bridge, the wire of length $1 m$ has a non-uniform cross-section such that, the variation $\frac{dR}{dl}$ of its resistance $R$ with length $l$ is $\frac{dR}{dl}\propto \frac{1}{\sqrt{l}}.$ Two equal resistances are connected as shown in the figure. The galvanometer has zero deflection when the jockey is at point $P.$ What is the length $AP?$

The galvanometer deflection, when key $K_1$ is closed but $K_2$ is open, equals ${\theta }_0$ (see figure). On closing $K_2$ also and adjusting $R_2$ to $5\Omega ,$ the deflection in galvanometer becomes $\frac{{\theta }_0}{5}.$ The resistance of the galvanometer is, then, given by [Neglect the internal resistance of battery]:

How much work is done in moving a charge of $2 \mathrm{C}$ across two points having a potential difference $10 \mathrm{V}$?