The value of the resistance $R$ in the figure is adjusted such that the power dissipated in the $2\,\Omega$ resistor is maximum. Under this condition:

Two voltmeters $V_1$ and $V_2$ are connected in series in a $D.C.$ circuit. The reading of $V_1$ is $80 \, V$ and its sensitivity is $200 \, \Omega/V$. If the resistance of $V_2$ is $32 \, k\Omega$,what is the total voltage of the circuit in $V$?

The $V-i$ graphs for a conductor at temperatures $T_1$ and $T_2$ are shown. $(T_2 - T_1)$ is proportional to:

Two resistances $R_1$ and $R_2$ when connected in series and parallel with a $120\, V$ line,the power consumed is $25\, W$ and $100\, W$ respectively. The ratio of the power consumed by $R_1$ to that consumed by $R_2$ is:

The Peltier coefficient of a thermocouple is $2 \times 10^{-9} \, V$. How much heat is developed at a junction if a $2.5 \, A$ current flows for $2 \, min$?

The two ends of a uniform conductor are joined to a cell of $e.m.f.$ $E$ and some internal resistance. Starting from the midpoint $P$ of the conductor,we move in the direction of current and return to $P$. The potential $V$ at every point on the path is plotted against the distance covered $(x)$. Which of the following graphs best represents the resulting curve?