A student designs a portable immersion heater by submerging a nichrome coil with…
PHYSICS · Multi-part · AP · Physics 2: Algebra-based · Electric Circuits · Electric Circuits
Problem
A student designs a portable immersion heater by submerging a nichrome coil with resistance 30 Ω into 0.50 kg of water initially at 20 °C. The coil is connected to a 120 V battery using ideal leads. Assume the coil’s resistance remains constant and that the water is perfectly stirred so its temperature is uniform at all times. While the heater is on, 30 % of the electrical energy delivered to the coil is lost to the surroundings instead of heating the water.
(a) Calculate the current through the coil.
(b) Determine the rate at which electrical energy is converted to thermal energy in the coil.
(c) Determine the minimum time required for the water to reach 100 °C.
(d) During the time interval found in part (c), compute the total charge that passes through the coil.