TSSPDCL JLM SPECIAL | Ripple frequency of fuel wave rectifier is?

1. Which of the following is a secondary cell
a. Voltaic cell
b. Daniel cell
c. Primary cell
d. Lead acid cell
2. The ratio of RMS value to average value of an alternating quantity is known as
a.Power factor b.Peak factor
c.Form factor d.Pitch factor
3. VI cos ∅ is called
a.Reactive power
b.Real power
c.Apparent power
4.Total power
4. A tolerance band of 20% in the value of carbon resistor is represented by
a.Gold band b.Black band
c.Silver band d.Without any band
5. Which of the following is a semi conductor
a.Copper b.Aluminium
c.Silver d.Silicon
6. Unit of heat energy is
a.KWH b.KVA
c.KVAR d.KCAL
7. The capacity of storage cell is measured in
a.Amp-hour b.Watt-hour
c.Joule d.Coulomb
8. Two identical coils are having self inductance of 4mH with mutual inductance between them is 3mH the co efficiency coupling is ____
a.1 b.1.5 c.0.75 d.2
9. Which of the following are insulators
a.Rubber b.Glass
c.P.V.C. d.All the above
10. The unit of magneto motive force is
a.Weber b.Amp/m
c.Henry d.Amp-turn
11. The quantity efficiency of a lead acid battery is between
a.90-95% b.72-78%
c.60-65% d.10-15%
12. A 24V lead acid –storage battery has 12 numbers of 2V cell
a.All in parallel b.All in series
c.Both a and b d.None
13. In dc generators lap winding is used for
a.Low voltage, low current
b.Low voltage high current
c.High voltage, high current
d.High voltage low current
14. Aluminium is a ——-
a.Paramagnetic material
b.Diamagnetic material
c.Ferro magnetic material
d.Soft magnetic material
15. Inter poles in DC machines are used for
a.Increase voltage
b.Increase current
c.Balancing induced emf
d.Improving commutation
16. The transformer are working on the principle of
a.Conversion energy
b.Eddy current
c.Self induction
d.Mutual induction
17. Fuse wire is prepared using
a.Copper b.Aluminium
c.Lead and tin d.Silver and iron
18. A dynamo
a.Converts mechanical energy to electrical energy
b.Converts EE to ME
c. Creates mechanical energy
d.Amplify electrical energy
19. A six pole generator has 2 parallel paths. The generator is wound in___
a.Lap winding
b.Ware winding
c.Concentric winding
d.All the above
20. BHP stands for
a.British horse power
b.British high power
c.Belt horse power
d.Break horse power
21. The brush voltage drop in dc motor is usually in the order of
a.2V b.10V c.20V d.50V
22. The most effective damping is
a.Fluid friction b.Electromagnetic
c.Air friction
d.Eddy current
23. A doped semi conductor is also known as
a.A semiconductor
b.Diffused semi conductor
c.Intrinsic semi conductor
d.Extrinsic semi conductor
24. Which of the following has the highest mobility?
a.Neutron b.Electron
c.Positive ion d.Negative ion
25. The value of β interms of ∝_____
a.β=∝/(1+∝) b.β=∝/(1-∝)
c.β=1/(1-∝) d. none
26. The gain of voltage amplifier is 60dB. It is numerically equal to
a.60 b.100 c.1000 d.10000
27. In an oscillator
a.There is no feedback
b.There is a negative feedback
c.There is a positive feedback
d.There can be either positive or negative feedback
28. The PIV of each diode in a fuel wave bridge rectifier is
a.Vm/2 b.2Vm
c.Vm d.None
29. In a thyristor holding current is
a.More than latching current Il
b.Less than Il
c.Equal to Il d.Very small
30. If “NS” is the synchronous speed, then speed of the motor Nr
a.NS b.SNS
c.(1-S)NS d.(NS-1)S
31. The frequency of the rotating magnetic field produced in the rotor is equal to
a. Slip x supply frequency
b.Supply frequency
c.Supply frequency
d.None
32. For ceiling fans, generally the single phase motor used is
a.Split phase type
b.Capacitor start type
c.Capacitor start and run type
d.Permanent capacitor
33. In a 3-phase supply. The phase angle between any two phase is
a.600 b.900 c.1200 d.1800
34. The power developed by a sync hronous machine maximum when load angle
a.Zero b.450
c.900 d.1200

ANS:- 1.d 2.c 3.b 4.c 5.d 6.d 7.a 8.c 9.d 10.d 11.a 12.b 13.b 14.b 15.d 16.d 17.c 18.a 19.b 20.a 21.a 22.d 23.d 24.b 25.b 26.c 27.c 28.c 29.b 30.c 31.a 32.c 33.c 34.c

35. The speed regulation of a synch ronous machine is always
a.1% b.0.5% c.-1% d.Zero
36. The most common generation voltage in india
a.66KV b.33KV
c.11KV d.3.3KV
37. Salient poles are generally use on
a.High speed b.Low speed
c.zoth a and b d.None
38. The material used for control rod is
a.Heavy water b.Carbon
c.Boron d.Uranium
39. The efficiency of electrostatic precipitator is as high as
a.99.8% b.90%
c.85% d.80%
40. Water hammer is developed in
a.Surge tank b.Water turbine
c.Penstock d.Draft tube
41. As the frequency increase, the skin effect
a.Decreases b.Remain same
c.Increases d.All the above
42. The number of insulator disc required to form a string for 400kv line around
a.15-16 b. 22-23
c.25-27 d.30-34
43. At hilly areas the corona loss
a.Increases b.Decreases
c.Remain in same d.None
44. In transmission lines we usually use cross arms made of
a.Aluminium b.Copper
c.Steel d.RCC
45. Between two supports, due to sag the conductor takes the form of
a.Semi circle b.Caternary
c.Hyper bola d.None
46. Moving iron instruments are used in
a.Ac only b.DC only
c.AC and DC d. All the above
47. Fuse wire have
a.High melting point
b.Low inductance
c.Low melting point
d.High resistance
48. SWG stands for
a.Standard wire group
b.Simple wire group
c.Standard wire gauge
d.Simple wire gauge
49. If a power factor of a circuit is unity, its reactive power is
a.Zero b.Unity
c.Maximum d.Minimum
50.____ motor is used for electric traction
a.DC series motor
b.DC shunt motor
c.Both A and B d.None
51. AC magnets are made of laminated iron to
a.For better induction
b.to reduce eddy current losses
c.for AC and DC used
d.to reduce reluctance
52. A 2KW ,200 V dc generator will supply a load current of
a.2 Amp b.5 Amp
c.20 Amp d.10 Amp
53. The synchronous speed of an 8 pole induction motor induction motor operates at 50Hz supply is
a.3000 rpm b.1000 rpm
c.1500 rpm d.750 rpm
54. Commutator in a dc motor
a.Converts DC to AC
b.Converts AC to DC
c.Invert AC to DC
d.Invert DC to AC
55. What is the unit of magnetic flux density
a.flux b.Tesla
c.mpere turn d.W b /m
56. One metric horse power is equal to
a.735.5 watts b.746 watts
c.760 watts d. 700 watts
57. The trade name of transformer oil
a. ASKARAL b.CASTROL
c.INDANE d.CRB
58. A 3-phase 20 KVA load is having 0.8 lagging power factor. The true power of the circuit is
a.16KW b.36KW
c.48KW d.75KW
59. Secondary of current trans former will have
a.More turns a thick gauge
b.Less turns of thin gauge
c.More turns of thin gauge
d.Less turns of thick gauge
60. What is the unit of Reactive power
a.KW b.KVAR
c.KVA d.All the above
61. The value of transformation ratio of step up transformer will be
a.Less than one b.Unity
c.More than one
d.None of the above
62. In NPN transistor P region is called
a.Collector b.Emitter
c.Base d.None
63. A moving iron ammeter reads 10A how big is the peak current of oscillations
a.7.07A b.1.414A
c.70.7A d.14.1A
64. Ripple frequency of fuel wave rectifier is
a.f input b. 2f input
c.3f input d. f/2 input
65. R.M.S Stands for ——–
a.Root mean square value
b.Root median square value
c.Root mean sinusoidal value
d.None of the above

 

ANS :- 35.d 36.c 37.b 38.c 39.a 40.c 41.c 42.b 43.a 44.c 45.b 46.c 47.c 48.c 49.a 50.a 51.b 52.d 53.d 54.d 55.b 56.a 57.a 58.a 59.c 60.b 61.c 62.c 63.d 64.b 65.a

 

Dr.Ashok babu
Easy Teach Institute
Dilsukhnagar, Hyd
9502092272