Top 250+ Solved Electrical and Electronics Engineering MCQ Questions Answer
Q. Wave wound genrators provide
a. less current but more voltage
b. more current but less voltage
c. more current but less voltage
d. none of the above
Q. A D.C. motor is still used in industrial applications because it____.
a. is cheap
b. is simple in construction
c. provides fine speed control
d. none of the above
Q. The field poles and armature of a D.C. machine are laminated to___.
a. reduce the weight of the machine
b. decrease the speed
c. reduce eddy currents
d. reduce armature reaction
Q. The value of back EMF in a DC motor is maximum at ____.
a. no load
b. full load
c. half of full load
d. none of the above
Q. The mechanical power developed in a dc motor is maximum when back emf (Eb) is equal to ------the applied voltage (V)
a. twice
b. half
c. one third
d. none of the above
Q. When the speed of dc motor increases , its armature current ----
a. increases
b. decreases
c. remains constant
d. none of the above
Q. The amount of back emf of a shunt motor will increase when
a. the load is increased
b. the field is weakened
c. the field is strengthened
d. none of the above
Q. The speed of a dc motor is
a. directly propotional to flux per pole
b. inversely propotional to flux per pole
c. inversely propotional to applied voltage
d. none of the above
Q. The torque developed by a dc motor is directly propotional to---
a. flux per pole x armature current
b. armature resistance x applied voltage
c. armature resistancex armature current
d. none of the above
Q. The shaft torque in a DC motor is less than total armature torque because of ____in the motor
a. cu losses
b. field losses
c. iron and friction lossees
d. none of the above
Q. In a DC motor the brushes shifted from the mechanical nuetral plane in a direction opposite to the rotation to _____.
a. decrease the speed
b. increase the speed
c. reduce sparking
d. produce flat characteristics
Q. The speed of a ____ motor is practically constant
a. cumulative compound
b. series
c. differential compound
d. shunt motor
Q. ____ motor is a variable speed motor.
a. series
b. shunt
c. cumulatively compounded
d. differetial compounded
Q. The most commonly used method of speed control of a DC motor is by varying ____.
a. voltage applied to a motor
b. field control
c. effective number of conductors in series
d. armature circuit resistance
Q. The running speed of a DC series motor is basically determined by _____.
a. field excitation
b. load
c. armature resistance
d. none of the above