Sparking at the commutator of a D.C. motor may result in____________?

A. Damage to commutator segments
B. Damage to commutator insulation
C. Increased power consumption
D. All of the above

In case of conductively compensated D.C. series motors, the compensating winding is provided______________?

A. As separately wound unit
B. In parallel with armature winding
C. In series with armature winding
D. In parallel with field winding

For the same H.P. rating and full load speed, following motor has poor starting torque_____________?

A. Shunt
B. Series
C. Differentially compounded
D. Cumulativelyc’ompounded

D.C. series motors are used______________?

A. Where load is constant
B. Where load changes frequently
C. Where constant operating speed is needed
D. In none of the above situations

If a D.C. shunt motor is working at no load and if shunt field circuit suddenly opens__________?

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

Which D.C. motor will be suitable along with flywheel for intermittent light and heavy loads?

A. Series motor
B. Shunt motor
C. Cumulatively compounded motor
D. Differentially compounded motor

Which D.C. motor has got maximum self loading property?

A. Series motor
B. Shunt motor
C. Cumulatively compounded ‘motor
D. Differentially compounded motor

The power mentioned on the name plate of an electric motor indicates____________?

A. The power drawn in kw
B. The power drawn in kva
C. The gross power
D. The output power available at the shaft

The current drawn by the armature of D.C. motor is directly proportional to__________?

A. The torque required
B. The speed of the motor
C. The voltage across the terminals
D. None of the above

In a D.C. series motor, if the armature current is reduced by 50%, the torque of the motor will be equal to

A. 100% of the previous value
B. 50% of the previous value
C. 25% of the previous value
D. 10% of the previous value