DC Motors
As there is no back e.m.f. at the instant of starting a D.C. motor, in order to prevent a heavy current from flowing though the armature circuit

A resistance is connected parallel to the armature
Armature is temporarily open circuited
A high value resistor is connected across the field winding
A resistance is connected in series with armature

ANSWER DOWNLOAD EXAMIANS APP

DC Motors
In variable speed motor

A weaker commutating field is needed at low speed than at high speed
None of these
Same commutating field is needed at low speed than at high speed
A stronger commutating field is needed at low speed than at high speed

ANSWER DOWNLOAD EXAMIANS APP

DC Motors
The speed of a dc motor is

inversely proportional to applied voltage
inversely proportional to flux per pole
Directly proportional to flux per pole
None of the listed here

ANSWER DOWNLOAD EXAMIANS APP

DC Motors
If a D.C. shunt motor is working at no load and if shunt field circuit suddenly opens

Motor will run at very slow speed
This will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses
Nothing will happen to the motor
This will make armature to take heavy current, possibly burning it

ANSWER DOWNLOAD EXAMIANS APP
MORE MCQ ON DC Motors