An electric heater of resistance $6 \, \Omega$ is run for $10 \, \text{minutes}$ on a $120 \, \text{V}$ line. The energy liberated in this period of time is:

$A$ button battery is rated $3 \,V$ and $225 \,mAh$. $A$ cricket ball (mass $= 0.163 \,kg$) having energy equal to that stored in the battery will have a speed closest to ............ $\,m/s$.

$A$ $10\, \Omega$ electric heater operates on a $110\, V$ line. Calculate the rate at which it develops heat in $watts$.

$A$ potential $V_0$ is applied across a uniform wire of resistance $R$. The power dissipation is $P_1$. The wire is then cut into two equal halves and a potential of $V_0$ is applied across the length of each half. The total power dissipation across two wires is $P_2$. The ratio $P_2: P_1$ is $\sqrt{x}: 1$. The value of $x$ is $.............$.

What is the maximum power output that can be obtained from a cell of $\operatorname{emf} E$ and internal resistance $r$?

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