A torch bulb is rated $2.5 \mathrm{V}$ and $750 \mathrm{mA}$. Calculate: its resistance.

Two lamps, one rated $60 \mathrm{W}$ at $220 \mathrm{V}$ and other $40 \mathrm{W}$ at $220 \mathrm{V}$, are connected parallel to the electric supply of $200 \mathrm{V}$. Calculate the current drawn from the electric supply.

Two lamps, one rated $60 \mathrm{W}$ at $220 \mathrm{V}$ and other $40 \mathrm{W}$ at $220 \mathrm{V}$, are connected parallel to the electric supply of $200 \mathrm{V}$. Calculate the total energy consumed by two lamps together when they operate for $1$ hour.

${\mathrm{B}}_1$, ${\mathrm{B}}_2$ and ${\mathrm{B}}_3$ are three identical bulbs connected as shown in figure. When all the three bulbs glow, a current of $3 \mathrm{A}$ is recorded by the ammeter A. What happens to the glow of the other two bulbs when the bulb ${\mathrm{B}}_1$ gets fused?