Electrical Engineering Questions And Answers :: Dc Motors: part4



Electrical Engineering : Dc Motors QUESTIONS AND ANSWERS :: part4 : 6 to 10

Following Electrical Engineering Multiple choice objective type questions and answers will help you in BSNL JTO, GATE 2021 and IES 2021 examinations :

6.D.C. shunt motors are used for driving

trains
cranes
hoists
machine tools

7.The main disadvantage of the Ward-Leonard control method is

high initial cost
high maintenance cost
low efficiency at Hght loads
all of the above

8.Which of the following motors is usually used in house-hold refrigerators ?

D.C. shunt motor
D.C. series motor
Single phase induction motor (split phase start or induction run motor)
Reluctance motor

9.Regenerative method of braking is based on that

back e.m.f. is less than the applied voltage
back e.m.f. is equal to the applied voltage
back e.m.f. of rotor is more than the applied voltage
none of the above

10.In Ward-Leonard control the lower limit of speed is imposed by

residual magnetism of the generator
core losses of motor
mechanical losses of motor and gen´┐Żerator together
all of the above

More Dc Motors QUESTIONS AND ANSWERS available in next pages

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