# When the electric motor is connected to a network with a voltage of U = 220V, it consumes current I = 5

**When the electric motor is connected to a network with a voltage of U = 220V, it consumes current I = 5. determine the power consumed by the motor and its efficiency, if the resistance R of the winding is 6 ohms.**

Let us first find the resistance of the electric motor according to the formula voltage divided by current:

R = U / I = 220 V / 5 A.

R = 44 ohms.

The resistance of the winding is denoted by a small letter r.

Now let’s find the cardinality – it will be equal to:

P = U ^ (2) / R = U * I = I ^ (2) * R = 220 * 5 = 220 ^ (2) / 44 = 5 ^ (2) * 44 = 1100 W.

The efficiency will be equal to the ratio of useful work to spent:

n = Ap / As = (U * I) / (E * I) = U / E = (I * R) / ((I * (R + r)) = R / (R + r).

n = 44 / (44 + 6).

n = 44/50.

n = 0.88.

Answer: P = 1100 W. n = 0.88.