Question
(a) An immersion heater utilizing 120 V can raise the temperature of a $1.00 \times 10^2 \textrm{ g}$ aluminum cup containing 350 g of water from $20.0^\circ\textrm{C}$ to $95.0^\circ\textrm{C}$ in 2.00 min. Find its resistance, assuming it is constant during the process. (b) A lower resistance would shorten the heating time. Discuss the practical limits to speeding the heating by lowering the resistance.
1. $14.8 \Omega$
2. A lower resistance would increase the current. There's a limit to how much current the power supply can provide before tripping a circuit breaker.
Solution Video