Two bulbs have resistances in the ratio $1 : 2$. They are connected in parallel to a constant voltage source. What is the ratio of power dissipated in them?

If two electric bulbs have $40\, W$ and $60\, W$ rating at $220\, V$,then the ratio of their resistances will be

In an electrical circuit,a battery is connected to pass $20\, C$ of charge through it in a certain given time. The potential difference between two plates of the battery is maintained at $15\, V$. The work done by the battery is ........... $J$.

The figure shows a thick spherical shell made of a material with electrical conductivity $\sigma$. It has inner and outer radii of $10\ cm$ and $20\ cm$ respectively and is filled with ice inside. Its inner and outer surfaces are kept at different potentials by a battery with internal resistance $r = \frac{2}{\pi}\ \Omega$ and electromotive force $\epsilon = 5\ V$. Find the value of $\sigma$ for which the ice melts at the maximum possible rate,given that $25\%$ of the heat generated by the shell due to Joule heating is used to melt the ice.

$A$ $60\,W$ bulb operates on a $220\,V$ supply. The current flowing through the bulb is:

In a $Ag$ voltameter,$2.68 \, g$ of silver is deposited in $10 \, \min$. The heat developed in a $20 \, \Omega$ resistor during the same period will be: