A. where load is constant
B. where load changes frequently
C. where constant operating speed is needed
D. in none of the above situations
Related Mcqs:
- When two D.C. series motors are connected in parallel, the resultant speed is____________?
A. more than the normal speed
B. loss than the normal speed
C. normal speed
D. zero - 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 - Which of the following tests will be suitable for testing two similar D.C. series motors of large capacity ?
A. Swinburne’s test
B. Hopkinson’s test
C. Field test
D. Brake test - Differentially compound D.C. motors can find applications requiring___________?
A. high starting torque
B. low starting torque
C. variable speed
D. frequent on-off cycles - Starters are used with D.C. motors because______________?
A. these motors have high starting torque
B. these motors are not self-starting
C. back e.m.f. of these motors is zero initially
D. to restrict armature current as there is no back e.m.f. while starting - In D.C. shunt motors as load is reduced__________________?
A. the speed will increase abruptly
B. the speed will increase in proportion to reduction in load
C. the speed will remain almost/constant
D. the speed will reduce - In case of D.C. shunt motors the speed is dependent on back e.m.f. only because____________?
A. back e.m.f. is equal to armature drop
B. armature drop is negligible
C. flux is proportional to armature current
D. flux is practically constant in D:C. shunt motors - These days D.C. motors are widely used in____________?
A. pumping sets
B. air compressors
C. electric traction
D. machine shops - Which of the following motors one will choose to drive the rotary compressor ?
A. D.C. shunt motor
B. D.C. series motor
C. Universal motor
D. Synchronous motor - Which of the following motors is most suitable for signalling devices and many kinds of timers ?
A. D.C. shunt motor
B. D.C. series motor
C. Induction motor
D. Reluctance motor
