The power is 400W. The voltage is 220V. The current is 2.9a. The frequency is 50Hz. How much electricity does it take in an hour? The answer must be 100% correct. The formula and the meaning of the letters in the formula must be written clearly. And the unit

The power is 400W. The voltage is 220V. The current is 2.9a. The frequency is 50Hz. How much electricity does it take in an hour? The answer must be 100% correct. The formula and the meaning of the letters in the formula must be written clearly. And the unit

Known: rated power is 400W (W), current is 2.9a (a), voltage is 220V (V), frequency is 50 Hz (Hz), time is 1 hour. Ask: how many kilowatts of electricity to use? P = UI = 220V (V) * 2.9a (a) = 638w (W) = 0.638kw (kw) w = Pt = 0.638kw (kw) * 1H (

There is a lamp with power of 18 watts and voltage of 220 volts on it. What is the current when it works normally?
How to calculate and how large fuse should be used?
For example, a motor P = 35W, u = 220V, can we calculate its rated current and internal resistance at rest from these conditions?

The rated current of the motor is marked on its nameplate. I = P / (√ 3 * u * cos φ * η) P is the power (output mechanical power) W, u is the line voltage V, cos φ is the power factor, η is the efficiency. The lamp itself is marked with 18 Watts voltage 220 V? The lamp is directly connected to 220 V? What lamp is it? If it is an incandescent lamp, I = 18

The voltage at both ends of a resistor increases from 2 V to 3 V, and the current through it increases by 0.2 a

5Ω
The formula defined by resistance is as follows:
R = U1 / I1 = U2 / I2
R = (u2-u1) / (i2-i1), where U2 = 3V, U1 = 2V, i2-i1 = 0.2A
R=(3-2)/0.2Ω=5Ω

The voltage at both ends of a resistor is 3V and the current through it is 1a. When the voltage at both ends increases by 6V, the power increases by ()
A. 3W B. 9W C. 12W D. 24W

The resistance value r = u1i1 = 3v1a = 3 Ω, and the electric power P1 = u1i1 = 3V × 1A = 3W; when the voltage at both ends of the resistance increases by 6V, the voltage at both ends of the resistance U2 = U1 + △ u = 3V + 6V = 9V, and the electric power P2 = u22r = (9V) 23 Ω = 27W; therefore, the increase of resistance power △ P = p2-p1 = 27w-3w = 24W