ELECTRIC DRIVE MCQ TYPE QUESTIONS
1. THE heating time constanat of an electrical machines gives an induction of its
Ans- cooling
2. Intermitted duty rating of an electric motor
Ans- is equal to name plate rating
3. To get the speed higher than the base speed of a dc shunt motar
Ans- field control is used
4. Starting current of a motar is kept low
Ans- to avoid excessive heating
5. If slip value is less than 1, it means the machine is
Ans- Generating
6. The method of interchanging the input supply terminals of the motor is called
Ans- plugging
7. Calculate the flux produced by the Dc series field winding using the following data , Ia = 5A, Ra=2, Eb=20
Ans- Vt= Eb +IaRa
= 20+5×2
= 30v
8. 20v ,10A, 10rpm separately excited dc motar with armature resistance equal to 0.8 ohms . Calculate back emf developed in the motar when it operates on the full load
Ans- Eb= Vt- I×Ra
= 20 - 10×0.8
= 20 - 8
= 12v
9. Which barking is not possible in series motar ?
Ans- Regenerative braking
10. The armature of the Dc shunt motar is proportional to
Ans- Armature current only
11. A class 1 contactor should be mechanically servd to withstand
Ans- 0.025 million times
12. Which of the following pair is used for frequency converter
Ans- squarel cage induction motor and wound rotar induction motor
13. In the jaw crushers, a motar has to often start against
Ans- Heavy load
14. Which of the following motar is preferred for synthetic fiber mills
Ans- Reluctance motar
15. The Power factor of the reluctance motar at full load is
Ans-. 0.6 to 0.7
Wish you your exam goging very good
