A DC shunt generator delivers at 45A at a terminal voltage of 220V.The armature and the shunt field resistance are  and  respectively. The stray losses are 375W. The percentage efficiency of the DC generator is________________.

The armature resistance of a permanent magnet dc motor is 0.8Ω. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1400 rpm drawing a current of 3.5 A form the same source will be

In a dc motor running at 2000 rpm, the hysteresis and eddy current losses are 500W and 200W respectively. If the flux remains constant, calculate the speed at which the total iron losses are halved.

A DC shunt generator delivers 60KW at 240V and 360 rpm. The armature and field resistances are 0.015Ω and 60Ω respectively. Calculate the speed of the machine running as a shunt motor and taking 60KW input at 240V. Allow 1 volt per brush for contact drop.

A 5kW, 200V DC shunt motor has an armature resistance of 1 ohm and shunt field resistance of 100 ohms. At no-load, the motor draws 6A from a 200V supply and runs at 1000rpm. The rotational loss of the machine is… W and the no load torque is… N-m