Joule's Law — Prelims Questions

An electric heater of resistance $100,Omega$ is connected to a $200,\text{V}$ source. Calculate the heat generated by the heater in $5,\text{minutes}$.

Two wires, A and B, of the same material and length, have radii $r$ and $2r$ respectively. If they are connected in series to a battery, what is the ratio of heat produced in wire A to wire B in a given time?

An electric bulb is rated $100,\text{W}, 220,\text{V}$. If it is operated on a $110,\text{V}$ supply, what will be the power consumed by the bulb?

If the current through a resistor is doubled, how many times does the rate of heat production (power dissipated) increase?

Which of the following applications does NOT primarily rely on Joule's Law for its intended function?

Two resistors, $R_1$ and $R_2$, with $R_1 < R_2$, are connected in parallel to a voltage source. If $H_1$ and $H_2$ are the heats generated in $R_1$ and $R_2$ respectively in a given time $t$, what is the relationship between $H_1$ and $H_2$?