An electric motor operates on a `50V` d.c. supply draw a current of `15 A`. If the motor yields a mechanical power of `150 W` estimate the power dissipated across its windings. Also find the efficiency of the motor ?

Answer

`600 W,20%`

Explanation

Total power of moter
`P = VI = 50 xx 15 = 750 W`
mechhanical power of motor `P = 150 W`
power dissipated across the winding of motor
`= 750 - 150 = 600 W`
Efficiency of moter `= (P)/(P) xx 100 = (150)/(150) xx 100 = 20%`