D.C. Motors

A. increasing the resistance in armature circuit
B. increasing the resistance in field circuit
C. reducing the resistance in the field circuit
D. reducing the resistance in the armature circuit

A. a resistance is connected in series with armature
B. a resistance is connected parallel to the armature
C. armature is temporarily open circuited
D. a high value resistor is connected across the field winding

A. constant torque drive
B. constant voltage drive
C. constant current drive
D. none of the above

A. 2.36%
B. 4.76%
C. 6.77%
D. 8.84%

A. centrifugal pumps
B. elevators
C. steel rolling mills
D. colliery winders

A. Voltage control method
B. Field control method
C. Armature control method
D. All above methods

A. field flux only
B. armature current only
C. both A. and B.
D. none of the above

A. reduce slightly
B. increase slightly
C. increase proportionately
D. remains unchanged

A. Shunt motor
B. Series motor
C. Differential compound motor
D. Cumulative compound motor

A. D.C. series motor
B. D.C. shunt motor
C. induction motor
D. all of above motors