SSC JE electrical Mock Test Paper 2019| MES Electrical

Ques.31. The rotor poles of a 4 pole synchronous generator shift by 25 mechanical degrees from no-load to full-load. The torque angle at full-load is _________ degrees.

1. 80
2. 70
3. 50
4. 10

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Ques.32. If the bandwidth of an oscilloscope is given as direct current to 10 MHz, what is the latest rise time in a sine wave have to be produced accurately by the oscilloscope?

1. 35 nsec
2. 10 nsec
3. 3.5 nsec
4. 0.035 nsec

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Ques.33.In an R-C circuit, when the switch is closed, the response ____________

1. Do not vary with time
2. Decays with time
3. Rises with time
4. First increases and then decreases

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Ques.34. How many segments will be there for the commutator of a 6-pole DC machine having a simple wave wound armature with 72 slots?

1. 73
2. 72
3. 36
4. 18

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Ques.35. A 3-phase, 4-pole, 18 slot alternator is operating at rated speed. Find the slot angle(in degrees)?

1. 30
2. 39
3. 40
4. 42

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Ques.36.Using a grid of horizontally buried conductors a grounding system was formed which serves to dissipate the earth fault current, is called as –

1. Earth Grid
2. Earth Mat
3. Both (A) and (B)
4. Tower foot resistance

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Ques.37. When a ferromagnetic substance is magnetized, there are small changes in dimensions. The phenomenon is called

1. Hysteresis
2. Magnetostriction
3. Diamagnetism
4. Dipolar relaxation

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Ques.38. In a 3-phase, 6-pole, 50-Hz salient pole synchronous machine, the reluctance seen by the armature mmf changes ______ times in one sec.

1. 1
2. 2
3. 3
4. 0

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Ques.39.Consider the following statement regarding voltage stability definitions

1. A) A power system at a given operating state and subjected to a given disturbance is voltage stable if voltage near loads approach post-disturbance equilibrium values
   B) A power system at a given operating state and subjected to a given disturbance undergoes voltage collapse if post-disturbance equilibrium voltages are below acceptable limits.

Choose the correct option considering the above two statements?

1. A
2. B
3. Both
4. Neither A nor B

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Ques.40.The stator of a 3-phase, 6-pole a.c machine has 45 slots. The stator winding has 45 coils with a coil span of 6 slots. What type of winding will be selected for this machine?

1. Double-layer, fractional slot, short-pitched winding 
2. Single-layer, fractional slot, short-pitched winding
3. Single-layer, integral slot, full-pitch winding
4. Double-layer, fractional slot, full-pitch winding 

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