Which of the following loss in a D.C. generator is dissipated in the form of heat?

Torque developed by a D.C. motor depends upon_____________?

A. magnetic field
B. active length of the conductor
C. current flow through the conductors
D. number of conductors
E. radius of armature
F. all above factors

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

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

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
E. none of the above

Which one of the following is not the function of pole shoes in a D.C. machine ?

A. To reduce eddy current loss
B. To support the field coils
C. To spread out flux for better uniformity
D. To reduce the reluctance of the magnetic path

What will happen if the back e.m.f. of a D.C. motor vanishes suddenly?

A. The motor will stop
B. The motor will continue to run
C. The armature may burn
D. The motor will run noisy