SSC JE electrical question paper 2009

1. Earth fault relays are: ?

A) directional relays
B) non-directional relays
C) short operate time relays
D) long operate time relays

... Answer is B)
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2. The rating of fuse is expressed in terms of: ?

A) Amperes
B) Volts
C) VAR
D) KVA

... Answer is A)
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3. By burden of the relay we mean: ?

A) volt-ampere rating of relay
B) current rating of relay
C) voltage rating of relay
D) watt rating of relay

... Answer is D)
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4. Reactance relays are employed for phase fault in: ?

A) long line
B) medium line
C) short line
D) any of these

... Answer is C)
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5. The ratio of line-to-line capacitance and line-toneutral capacitance is: ?

A) 2 1
B) 4 1
C) 2
D) 4

... Answer is A)
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6. The material commonly used for sheaths of underground cable is: ?

A) lead
B) steel
C) rubber
D) copper

... Answer is A)
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7. . The recovery voltage will be maximum for power factor of: ?

A) zero
B) 0.5
C) 0.707
D) unity

... Answer is A)
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8. An air blast circuit breaker is usually employed for: ?

A) instantaneous voltage
B) intermittent duty
C) repeated duty
D) short duty

... Answer is C)
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9. Equation of continuity of flow is based on the principle of conservation of: ?

A) force
B) momentum
C) energy
D) mass

... Answer is D)
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10. Pitot tube is used for the measurement of ?

A) pressure
B) flow
C) discharge
D) velocity

... Answer is D)
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11. In a centrifugal pump, the liquid enters the pump: ?

A) at the top
B) at the bottom
C) at the centre
D) None of the above

... Answer is C)
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12. In reaction turbine: ?

A) kinetic energy is appreciable as the fluid leaves the runner and enters the draft tube
B) the vanes are partly filled
C) total energy of fluid is converted to kinetic energy in the runner
D) it is exposed to the atmosphere

... Answer is A)
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13. The value of current I flowing in the 1 Ω resistor in the circuit shown in the figure below will be: ?

A) 10A
B) 6A
C) 5A
D) Zero

... Answer is C)
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14. In the figure below, if we connect a source of 2- V, with internal resistance of 1Ω at AA’ with positive terminal at A, then current R is: ?

A) 2A
B) 1.66A
C) 1A
D) 0.625A

... Answer is D)
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15. The curve representing Ohm’s law is: ?

A) Linear
B) Hyperbolic
C) Parabolic
D) Triangular

... Answer is A)
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16. Specific resistance of a conductor depends upon: ?

A) Dimension of the conductor
B) Composition of conductor material
C) Resistance of the conductor
D) Both (a) and (b)

... Answer is B)
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17. Superposition theorem is essentially based on the concept of: ?

A) Reciprocity
B) Linearity
C) Duality
D) Non-linearity

... Answer is B)
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18. If a 500 KVA, 200 Hz transformer is operated at 50 Hz, its KVA rating will be: ?

A) 2000 KVA
B) 125 KVA
C) 250 KVA
D) 1000 KVA

... Answer is B)
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19. The angle between induced emf and terminal voltage on no-load for a single phase alternator is ?

A) 1800
B) 900
C) 00
D) 2700

... Answer is C)
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20. A salient pole synchronous generator connected to an infinite bus power will deliver maximum power at a power angle of: ?

A) δ = 0
B) δ = 900
C) δ = 450
D) δ = 300

... Answer is C)
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21. Starting torque of synchronous motor is: ?

A) very low
B) zero
C) very high
D) half-full load torque

... Answer is B)
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22. The power factor at which transformer operates: ?

A) is unity
B) is 0.8 lag
C) is 0.8 lead
D) depends upon the power factor of the load

... Answer is D)
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23. The efficiency of a 100 KVA transformer is 0.98 at full as well as half load. For this transformer at full load the copper loss: ?

A) is less than core loss
B) is equal to core loss
C) is more than core loss
D) All the above

... Answer is C)
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24. Which of the following will improve the mutual coupling between primary and secondary circuit ?

A) Transformer oil of high breakdown voltage
B) High reluctance magnetic core
C) Winding material of high resistivity
D) Low reluctance magnetic core

... Answer is D)
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25. High leakage transformers are of: ?

A) small voltage ampere rating
B) high voltage ampere rating
C) high voltage rating
D) low voltage rating

... Answer is B)
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26. The starting torque of a 3-phase induction motor varies as:l ?

A) V2 /V2
B) R K
C) A S
D) M S

... Answer is A)
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27. In a 3-phase induction motor, the mechanical power developed; in terms of air gap power Pg is: ?

A) (1 – S)Pg
B) PgS
C) S Pg 1−
D) S Pg

... Answer is A)
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28. The negative phase sequence in a 3-phase synchronous motor exists when the motor is: ?

A) underload
B) overloaded
C) supplied with unbalanced voltage
D) hot

... Answer is C)
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29. A centre zero ammeter connected in the rotor circle of a 6 pole, 50 Hz induction motor makes 30 oscillations in one minute. The rotor speed is: ?

A) 670 rpm
B) 990 rpm
C) 1010 rpm
D) 1030 rpm

... Answer is B)
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30. The permissible variation of frequency in power system Ps is: ?

A) ± 1%
B) ± 3%
C) ± 5%
D) ± 10%

... Answer is B)
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31. For coding of large size generators hydrogen is used because: ?

A) it offers reduced fire risk
B) it is light in weight
C) it is of high thermal conductivity
D) All the above

... Answer is D)
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32. The connected load of a consumer is 12 kW and his maximum demand is 1.5 kW. The demand factor of the consumer is: ?

A) 0.75
B) 0.375
C) 1.33
D) 1

... Answer is A)
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33. To meet the reactive power requirements at load centres usually: ?

A) shunt capacitors are used
B) series capacitors are used
C) shunt reactors are used
D) tap changing transformers are used

... Answer is A)
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34. The power factor will be leading in case of: ?

A) Dielectric heating
B) Resistance heating
C) Induction heating
D) All the above

... Answer is A)
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35. First law of thermodynamics furnishes the relationship between: ?

A) heat and work
B) heat work and properties of the system
C) various properties of the system
D) various thermodynamic processes

... Answer is B)
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36. Which instrument has the lowest resistance ?

A) Voltmer
B) Megger
C) Ammeter
D) Frequency meter

... Answer is C)
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37. The moving coil in a dynamometer wattmeter is connected: ?

A) in series with the fixed coil
B) across the supply
C) in series with the load
D) Any one of the above

... Answer is B)
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38. In arc welding, arc is created between the electrode and work by: ?

A) flow of current
B) voltage
C) material characteristics
D) contact resistance

... Answer is D)
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39. In a R-L-C circuit susceptance is equal to: ?

A) Equal to 1/X
B) Equal to 1/R
C) Equal to R/$Z^2$
D) Equal to X/$Z^2$

... Answer is A)
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40. The current read by the ammeter A in the AC circuit shown in following figure is: ?

A) 9A
B) 5A
C) 3A
D) 1A

... Answer is B)
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41. A 4-pole generator with 16 coils has a two layer lap winding. The pole pitch is: ?

A) 32
B) 16
C) 8
D) 4

... Answer is D)
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42. Two coupled coils with L1 = L2 = 0.6 H have a coupling coefficient of K = 0.8 The turn ratio N1/N2 ?

A) 4
B) 0.5
C) 1
D) 2

... Answer is C)
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43. The voltage across the various elements are marked, as shown in the figure given below. The input voltage is: ?

A) 27 V
B) 24V
C) 10 V
D) 5V

... Answer is D)
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44. The principle of dynamically induced emf is utilised is: ?

A) Choke
B) Thermocouple
C) Generator
D) Transformer

... Answer is C)
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