In the following circuit diagram, the current flowing through resistor $\frac{1}{4}\Omega$ of is

   

$ABCD$ is a square where each side is a uniform wire of resistance $1\mathrm{\Omega }$. A point $E$ lies on $CD$ such that if a uniform wire of resistance $1\mathrm{\Omega }$ is connected across $AE$ and constant potential difference is applied across $A$ and $C$ then $B$ and $E$ are equipotential : 

In the box shown current $i$ enters at $H$ and leaves at $C$. If $i_{AB}=\frac{i}{6},i_{DC}=\frac{2i}{3},i_{HA}=\frac{i}{2},i_{GF}=\frac{i}{6},i_{HE}=\frac{i}{6}$ choose the branch in which current is zero
 

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

Under what conditions current passing through the resistance $R$ can be increased by short circuiting the battery of $\mathit{emf}\mathit{ }{E}_2$. The internal resistances of the two batteries are $r_1$ and $r_2$, respectively.
 

 A milliammeter of range $10\mathrm{mA}$ and resistance $9\Omega$ is joined in a circuit as shown. The metre gives full-scale deflection for current $I$ when $A$ and $B$ are used as its terminals, i.e., current enters at $A$ and leaves at $B$ ($C$ is left isolated). The value of $\mathrm{I}$ is 

In the arrangement shown in the figure when the switch $S_2$ is open, the galvanometer shows no deflection for $l=\frac{L}{2}$. When the switch
$S_2$ is closed, the galvanometer shows no deflection for $l=\frac{5}{12}L$. The internal resistance $\left(\mathrm{r}\right)$ of $6 \mathrm{V}$ cell, and the emf $E$ of the other battery are respectively.

The variation of current $\left(I\right)$ and voltage $\left(V\right)$ is as shown in figure $A$. The variation of power $P$ with current $I$ is best shown by which of the following graph