DC Motors Online Test Questions - Set 05 - ObjectiveBooks

# Practice Test: Question Set - 05

1. As the load is increased the speed of D.C. shunt motor will
(A) Reduce slightly
(B) Increase slightly
(C) Increase proportionately
(D) Remains unchanged

2. At the instant of starting when a D.C. motor is put on supply, it behaves like
(A) A highly resistive circuit
(B) A low resistance circuit
(C) A capacitive circuit
(D) None of the above

3. Ward-Leonard control is basically a
(A) Voltage control method
(B) Field diverter method
(C) Field control method
(D) Armature resistance control method

4. Which of the following steps is likely to result in reduction of hysteresis loss in a D.C. generator?
(A) Providing laminations in armature core
(B) Providing laminations in stator
(C) Using nonmagnetic material for frame
(D) Using material of low hysteresis coefficient for armature core material

5. 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

6. Which D.C. motor has got maximum self relieving property?
(A) Series motor
(B) Shunt motor
(C) Cumulatively compounded motor
(D) Differentially compounded motor

7. If a D.C. motor is to be selected for conveyors, which rioter would be preferred?
(A) Series motor
(B) Shunt motor
(C) Differentially compound motor
(D) Cumulative compound motor

8. To get the speed of D.C, motor below the normal without wastage of electrical energy is used.
(A) Ward Leonard control
(B) Rheostat control
(C) Any of the above method
(D) None of the above method

9. In case the conditions for maximum power for a D.C. motor are established, the efficiency of the motor will be
(A) 100%
(B) Around 90%
(C) Anywhere between 75% and 90%
(D) Less than 50%

10. 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

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