DC Motors MCQs

If the field winding of an unloaded de shunt motor gets opened while running, it will

A de cumulatively compounded motor delivers rated load torque at rated speed. If the series field is short-circuited, then the armature current and speed will

A dc cumulatively compounded generator was operating satisfactorily and supplying power to on infinite bus when the mechaisal power supply from the prime mover failed. The machine will then run as a

A dc shunt generator builds up to a voltage of 220 V at no-load while running at its rates speed. If the speed of the generator is raised by 25% keeping the circuit conditions unaltered, then the voltage to which the machine would build up will

Two identical loss-less series motors connected in series across a dc supply voltage, run at speeds of N1 and N2, The ratio of their output powers will be

In a dc machine, the demagnetising effect of armature reaction is due to

Plugging of dc motors is normally done bY

A dc shunt wound motor finds application in

In dc machine, the field system has to be provided on stator unlike synchronous machines wherein it could be on any member, because