Which of the following represents a $volt$?

Four equal resistances dissipate $5 \, W$ of power together when connected in series to a battery of negligible internal resistance. The total power dissipated in these resistances when connected in parallel across the same battery would be ........... $W$.

In an electrical cable,there is a single wire of copper with a radius of $9 \, mm$. Its resistance is $5 \, \Omega$. The cable is replaced by $6$ different insulated copper wires,each with a radius of $3 \, mm$. Now,the total resistance of the cable will be ............... $\Omega$.

The ends of an element of zinc wire are kept at a small temperature difference $\Delta T$ and a small current $I$ is passed through the wire. Then, the heat developed per unit time

One junction of a certain thermoelectric couple is at a fixed temperature $T_r$ and the other junction is at temperature $T$. The thermo electromotive force for this is expressed by $E = K(T - T_r) \left[ T_0 - \frac{1}{2}(T + T_r) \right]$. At temperature $T = \frac{1}{2}T_0$,the thermoelectric power is

In the circuit shown in the figure,find the current through the $4\,\Omega$ resistor.