What is the actual power of a 220 V, 44 w appliance used in a 110 V circuit

What is the actual power of a 220 V, 44 w appliance used in a 110 V circuit

First, the resistance is 1100 Ω, and then the power is 11W

What is the electric power of an electric water heater with rated voltage of 220 V, capacity of 100 L and resistance of 24.2 Ω?

There is voltage and resistance. If you can work out the current, power is voltage times current

The rated power and voltage of a water heater are 800W and 220V respectively

R=U^2/P
=(220V)^2/800W
=60.5 euro

How does the current flow in the resistor? I have a 1a, 5V constant current source, which is added to a 50 ohm resistor. What is the current in the resistor?
Because it is a constant current source, the current in the circuit is 1a, and the resistance is 50 ohm. Isn't the voltage applied at both ends of the resistance 50V? It's much higher than the voltage of the constant current source. If the current in the resistance is less than 1a, it's not a series circuit, and the current is not equal everywhere. If the current can't be added to the resistance, but there is a voltage difference between the two sides of the resistance, why can't I add it?

Constant current source has a maximum output voltage limit. In your application, the maximum output voltage is 5V. When 1A current flows through a 50 ohm resistor, the required voltage must reach 50V. However, due to the maximum output voltage limit of 5V, the current in the resistor is 100mA, so the constant current source can't keep constant current, which is equivalent to constant voltage source