An electric heater is used to heat up 3.00× 102 kg of water from 10.0°C to 80.0°C in twenty minutes. Assuming that the heater is connected to a 120-V (rms) source and all electric power is used to heat the water, what is the resistance of the coil in the heater? The specific heat of water is 4186 J/(kg K).
The current going through a battery is I1 when it is connected to a resistor of resistance R1. If a second resistor of resistance R2 is added to the circuit parallel to the first resistor, the current through the battery increases to 3I1. What is the ratio R1/R2?
When a 14.4-V car battery delivers a current of 60.0 A, the power consumed on its internal resistance is 36.0 W, what is
(a) the internal resistance of the battery and
(b) the resistance of the load?