Xiao Li's family has a 220V 2000W water heater. The water heater works normally. How many joules does it consume in 5h

Xiao Li's family has a 220V 2000W water heater. The water heater works normally. How many joules does it consume in 5h

1kW is one degree power, 2kW is two degree power, 3KW is

The rated power of an electric fan is 60W, and the internal resistance is 2 Ω. When it is connected to the voltage of 220V, it can operate normally. The following are the requirements: (1) when the electric fan operates normally, what is the current intensity through it? How much electrical energy is converted into mechanical energy per second? (2) If the fan can't rotate after the power supply is connected, what is the current intensity through it? What is the actual power consumption of the electric fan?

(1) From P = UI: I = Pu = 60220 = 311a, then the heating power on the internal resistance of the electric fan: P heat = I2R = (311) 2 × 2 = 18121w ≈ 0.15w & nbsp; & nbsp; & nbsp; & nbsp; according to the law of conservation of energy: P machine = P rating - P heat = 60-0.15 = 59.85w (2) according to Ohm's law, I '= ur = 2202 = 110A heating