If the work done to take $3 \,C$ electric charge from one point to another point is $15 \,J$,what will be the potential difference between these two points (in $,V$)?

$A$ piece of wire is redrawn,without change in volume,so that its radius is halved. Compare the new resistance with the original resistance.

The resistivity of semiconductor materials is $..........$.

The voltage-current variation of two metallic wires $X$ and $Y$ at constant temperature are shown below. Assuming that the wires have the same length and the same diameter, explain which of the two wires will have larger resistivity.

What are the units of resistance?

$B_{1}$,$B_{2}$ and $B_{3}$ are three identical bulbs connected as shown in the figure. When all the three bulbs glow,a current of $3 \, A$ is recorded by the ammeter $A$.
$(i)$ What happens to the glow of the other two bulbs when the bulb $B_{1}$ gets fused?
$(ii)$ What happens to the reading of $A_{1}$,$A_{2}$,$A_{3}$ and $A$ when the bulb $B_{2}$ gets fused?