The e.m.f. of a cell is $E \text{ volts}$ and its internal resistance is $r \text{ ohm}$. The resistance in the external circuit is also $r \text{ ohm}$. The potential difference across the cell will be

The current flowing through $R_2$ is:

Consider an infinite ladder network shown in the figure. $V$ voltage $V$ is applied between the points $A$ and $B$. This applied voltage is halved after each section.

When an ammeter of negligible internal resistance is inserted in series with the circuit,it reads $1 \, A$. When a voltmeter of very large resistance is connected across $X$,it reads $1 \, V$. When points $A$ and $B$ (across $Y$) are shorted by a conducting wire,the voltmeter measures $10 \, V$ across the battery. The internal resistance of the battery is equal to .............. $\Omega$.

What is immaterial for an electric fuse wire?

Refer to the circuit shown. What will be the total power dissipation in the circuit if $P$ is the power dissipated in $R_1$ (in $P$)? It is given that $R_2 = 4 R_1$ and $R_3 = 12 R_1$.