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This set of Electrical and Electronics Engineering Multiple Choice Questions & Answers (MCQs) focuses on Electrical And Electronics Engineering Set 6
Q1 | The range of horse power of electric motor drives for rolling mills is of the order of
- 1 to 10 hp
- 15 to 25 hp
- 50 to 100 hp
- 100 to 500 hp
Q2 | Motors preferred for rolling mill drive is
- dc motors
- ac slip ring motors with speed control
- any of the above
- none of the above.
Q3 | Cumulatively compounded motors are used where we require _____.
- light duty excavators
- medium duty excavators
- heavy duty excavators
- all of the above
Q4 | Which type of motors are preferred in lifts?
- a. dc compound motors.
- b. dc series motors.
- c. dc shunt motors.
- d. none of the above.
Q5 | In cloth washing machines and refrigerators which motors are preferred?
- a. dc cumulative compound motors
- b. slip ring im
- c. stepper motor
- d. universal motors
Q6 | In lathes, milling and grinding machines which motor will preferred?
- a. dc shunt motors
- b. cage induction motor
- c. synchronous motor
- d. either a or b
Q7 | In planners which of following motors are preferred?
- a. dc shunt motor
- b. dc compound motor
- c. any of above
- none
Q8 | In iron and steel industry which motors are preferred?
- a. induction motors
- b. synchronous motors
- c. dc shunt wound motors
- d. pipe motors
Q9 | A sinusoidal voltage of frequency 1 Hz is applied to the field of a d.c generator. The armature voltage will be
- 1 hz square wave
- 1 hz sine wave
- d. c voltage
- zero
Q10 | In wave winding, the number of parallel paths of armature winding is
- p
- 2
- 4
- p/2
Q11 | The emf equation of dc generator is E=
- Øp/nza
- Øp60/nza
- Øpa/60nz
- Øpnz/60a
Q12 | If number of conductors in a dc generator is Z then total number of turns are
- z
- 2z
- z/2
- 4z
Q13 | What is the flux in the armature core section of a dc machine if the air gap flux be ø Wb?
- ø
- 0.1 ø
- 1.5 ø
- ø /2
Q14 | The flux leakage coefficient in dc machine is usually
- 0.6 to 0.8
- 1.05
- 1.2 to 1.3
- 2 to 2.5
Q15 | Armature resistance of a d.c. machine is about
- 25
- 200
- 100
- 0.1
Q16 | The electrical equivalent of gross mechanical power developed in a dc motor is
- vil
- ebil
- ebia
- ebish
Q17 | The armature torque is ------ that of shaft torque
- less than
- same as
- greater than
- none of these
Q18 | If the voltage equation of a dc motor is multiplied by ----- on both sides, we get power equation of dc motor
- ra
- v
- n
- ia
Q19 | The torque equation of a dc motor is --
- ta = 0.159Ø ia/2πpza
- ta = 0.159Øia/2πza
- ta = 0.159Øiaz/2πa
- ta = 0.159Øiapz/a
Q20 | The speed of dc motor is highest on
- no load
- 70% of full load
- 10% of full load
- 100% of full load
Q21 | With given power rating for lower current and higher voltage rating of a d.c. machine, one should prefer_________.
- lap winding
- wave winding
- none of these
- any of these
Q22 | If the number of poles in a lap wound generator be doubled, then the generated e.m.f will_________.
- become half
- become double
- increase to four times
- remains constant
Q23 | The counter emf of dc motor__________
- often exceeds the supply voltage
- aids the applied voltage
- helps in energy conversion
- regulates its armature voltage
Q24 | In a DC series motor increasing the load current will
- decrese the speed
- increase the speed
- better commutation
- increase the back emf
Q25 | The generator works on the principle of
- statically induced emf
- dynamically induced emf
- mutul induction
- kirchhoff\s law