Home / Electrical / SSC Junior Engineer Exam Paper-2017 Shift-2 (Electrical Engineering)

# SSC Junior Engineer Exam Paper-2017 Shift-2 (Electrical Engineering)

SSC Junior Engineer Exam Paper held on March 2017 Afternoon Shift (General Engineering)

Q 1 – A current is said to be alternating when it changes in _____.

Options:
1) Magnitude only
2) Direction only
3) Both magnitude and direction
4) None of these

Answer: Both magnitude and direction

Q 2 – The rms value of a sine wave is 100 A. Its peak value is _____.

Options:
1) 70.7 A
2) 141.4 A
3) 150 A
4) 282.8 A

Q 3 – A 50 Hz ac voltage is measured with a moving iron voltmeter and a rectifier type ac voltmeter connected in parallel. If the meter readings are V1 and V2respectively and the meters are free from calibration errors, then the form factor of the ac voltage may be estimated as _____.

Options:
1) V1/V2
2) 1.11 V1/V2
3) 2 V1/V2
4) π V1/2V2

Q 4 – The rms value of the resultant current in a wire which carries a dc current of 10 A and a sinusoidal alternating current of peak value 20 A is _____.

Options:

1) 14.1 A
2) 17.3 A
3) 22.4 A
4) 30 A

Q 5 – Two sinusoidal emfs are given as _____. e1=A sin(ωt+π/4) and e2=B sin(ωt-π/6). The phase difference between the two quantities, in degrees, is _____.
Options:
1) 75
2) 105
3) 60
4) 15

Q 6 – Which of the following statements pertains to resistor only?
Options:
1) they oppose sudden changes in voltages
2) they can act as energy storage devices
3) they can dissipate desirable amount of power
4) None of these

Answer: they can dissipate desirable amount of power

Q 7 – The current waveform in a pure resistor of Ω is shown in the given figure. Power dissipated in the resistor is:-

Q 8 – Purely inductive circuit takes power from the ac mains when _____.
Options:
1) both applied voltage and current increase
2) both applied voltage and current decrease
3) applied voltage decreases but current increases
4) applied voltage increases but current decreases

Answer: applied voltage decreases but current increases

Q 9 – A pure capacitance connected across 50 Hz, 230 V supply consumes 0.04 W. This consumption is attributed to _____.
Options:
1) ohmic loss due to ohmic resistance of plates
2) loss of energy in dielectric
3) capacitive reactance in ohms
4) Both ohmic loss due to ohmic resistance of plates and loss of energy in dielectric

Answer: Both ohmic loss due to ohmic resistance of plates and loss of energy in dielectric

Q 10 – A voltage of 50sin1000t V is applied across a parallel plate capacitor with plate area of 5 cm2 and plate separation gap of 5 mm. If the dielectric material in the capacitor has ?=2?0, then the capacitor current in (Amperes) will be _____.

Options:
1) [104/?0]cos103t
2) ?0104cos103t
3) [104/?0]sin103t
4) ?0104sin103t

Q 11 – For the AC circuit as shown below, if the rms voltage across the resistor is 120 V, what is the value of the inductor ?

Q 12 – The R-L circuit of the figure is fed from a constant magnitude variable frequency sinusoidal voltage source v_in. At 100 Hz, the R and L element each has a voltage drop Urms If the frequency of the source is changed to 50 Hz, then new voltage drop across R is:- Options:
1) Urms
2 Urms
3 Urms
4 Urms
Answer: Urms
Q 13 – A certain R-L series combination is connected across a 50 Hz single-phase ac supply. If the instantaneous power drawn was found to be negative for 2 milliseconds in one cycle, the power factor angle of the circuit must be _____.
Options:
1) 9°
2) 18°
3) 36°
4) 45°

Q 14 – The voltage phaser of a circuit is 10∠15°V and the current phasor is 2∠- 45°A. The active and reactive powers in the circuit are _____.

Options:
1) 10 W and 17.32 VAR
2) 5 W and 8.66 VAR
3) 20 W and 60 VAR
4) 20√2 W and 10√2 VAR

Answer: 10 W and 17.32 VAR

Q 15 – In an RLC circuit, supplied from an ac source, the reactive power is proportional to the

Options:
1) average energy stored in the electric field
2) average energy stored in the magnetic field
3) sum of the average energy stored in the electric field and that stored in the magnetic field
4) difference between the average energy stored in the electric field and that stored in the magnetic field

Answer: difference between the average energy stored in the electric field and that stored in the magnetic field

Q 16 – In gases the flow of current is due to _____.
Options:
1) Electrons only
2) Positive and negative ions
3) Electrons, positive ions
4) Electrons, positive ions and negative ions

Answer: Electrons, positive ions and negative ions

Q 17 – Ohm’s law is applicable to _____.
Options:
1) semiconductors
2) vacuum tubes
3) electrolytes
4) None of these

Answer: None of these

Q 18 – Pure metals generally have _____.
Options:
1) high conductivity and low temperature coefficient
2) high conductivity and large temperature coefficient
3) low conductivity and zero temperature coefficient
4) low conductivity and high temperature coefficient

Answer: high conductivity and large temperature coefficient

Q 19 – The insulation resistance of a cable of length 10 km is 1 MΩ. For a length of 100 km of same cable, the insulation resistance will be _____.
Options:
1) 1 MΩ
2) 10 MΩ
3) 0.1 MΩ
4) 0.01 MΩ

Q 20 – All the resistance in figure shown below are 1Ω each. The value of current ‘I’ is :-

Q 21 – Which of the following does not use heating effect of electric current?
Options:
1) Electric furnace
2) Geyser
3) Electric iron
4) Vacuum cleaner

Q 22 – In the figure given below, the value of :-

Q 23 – Four 100 W bulbs are connected in parallel across 200 V supply line. If one bulb gets fused _____.
Options:
1) no bulb will light
2) all the four bulbs will light
3) rest of the three bulbs will light
4) None of these

Answer: rest of the three bulbs will light

Q 24 – A 100 watt light bulb burns on an average of 10 hours a day for one week. The weekly consumption of energy will be _____.
Options:
1) 7 units
2) 70 units
3) 0.7 units
4) 0.07 units

Q 25 – The elements which are not capable of delivering energy by its own are known as _____.

Options:
1) unilateral elements
2) nonlinear elements
3) passive elements
4) active elements

[sociallocker]

Q 26 – A network has 4 nodes and 3 independent loops. What is the number of branches in the network?

Options:
1) 5
2) 6
3) 7
4) 8

Q 27 – A connected network of N > 2 nodes has at most one branch directly connecting any pair of nodes. The graph of the network _____.
Options:
1) must have at least N branches for one or more closed paths to exist
2) can have an unlimited number of branches
3) can only have at most N branches
4) can have a minimum number of branches not decided by N

Answer: must have at least N branches for one or more closed paths to exist

Q 28 –

Q 29 – Ideal voltage source have _____.

Options:
1) zero internal resistance
2) infinite internal resistance
3) low value of current
4) large value of emf

Answer: zero internal resistance

Q 30 – A voltage source having an open circuit voltage of 100 V and internal resistance of 50 Ω is equivalent to a current source _____.
Options:
1) 2 A in parallel with 50 Ω
2) 2 A in series with 50 Ω
3) 0.5 A in parallel with 50 Ω
4) 2 A in parallel with 100 Ω

Answer: 2 A in parallel with 50 Ω

Q 31 – Consider the circuit given below. What is the power delivered by the 24 V source ?

Q 32 – For the circuit shown what is the voltage V if the source voltage is reduced by 50% ?

Answer: (E/2) – IR

Q 33 – A coil wound over an iron carries certain current and establishes flux in the ring. If the area of a x-section of the ring is doubled, the flux density in the core _____.
Options:
1) is double of the previous value
2) is half of the previous value
3) is same as the previous value
4) is not possible to predict

Answer: is half of the previous value

Q 34 – A cast steel electromagnet has an air gap length of 0.3 cm. Find the ampere-turns for the air gap to produce a flux density of 0.7 Wb/m2 in the air gap.

Options:
1) 2100 AT
2) 1671 AT
3) 1447 AT
4) 167 AT

Q 35 – An air gap is usually inserted in magnetic circuits so as to _____.

Options:
1) prevent saturation
2) increase mmf
3) increase in flux
4) increase in inductance

Q 36 – Which of the following statements is correct?
Options:
1) The magnetic flux inside the exciting coil is the same as on its outer surface
2) The magnetic flux inside an exciting coil is zero
3) The magnetic flux inside the exciting coil is greater than that on its outside surface
4) The magnetic flux inside the exciting coil is lower than that on the outside surface

Answer: The magnetic flux inside the exciting coil is the same as on its outer surface

Q 37 – Consider the following statements:
The force per unit length between two stationary parallel wires carrying (steady) currents _____.
A. is inversely proportional to the separation of wires.
B. is proportional to the magnitude of each current.
C. satisfies Newton’s third law.
Out of these _____.
Options:
1) A and B are correct
2) B and C are correct
3) A and C are correct
4) A, B and C are correct

Answer: A, B and C are correct

Q 38 – A magnetic circuit requires 800 AT to produce a certain quantity of flux in magnetic circuit. If its excitation coil has 100 turns and 5 ohm resistance, the voltage to be applied in exciting coil is _____.
Options:
1) 60 V
2) 40 V
3) 80 V
4) 8 V

Q 39 – According to Faraday’s law of electromagnetic induction an emf is induced in a conductor whenever it _____.
Options:
1) lies in a magnetic field
2) lies perpendicular to the magnetic field
3) cuts the magnetic flux
4) moves parallel to the direction of magnetic field

Answer: cuts the magnetic flux

Q 40 – “In all cases electromagnetic induction, an induced voltage will cause a current to flow in a closed circuit in such a direction that the magnetic field which is caused by that current will oppose the change that produces the current”, is the original statement of _____.
Options:
1) Lenz’s law
2) Faraday’s law of magnetic induction
3) Fleming’s law of induction
4) Ampere’s law

Q 41 – A 500 kVA transformer has constant loss of 500 W and copper losses at full load are 2000 W. Then at what load, is the efficiency maximum?

Options:
1) 250 KVA
2) 500 kVA
3) 1000 kVA
4) 125 kVA

Q 42 – The all day efficiency of a transformer depends primarily on _____.

Options:
1) its copper losses
2) the amount of load
3) the duration of load
4) Both the amount and duration of load

Answer: Both the amount and duration of load

Q 43 – In a power transformer, the breather is provided in order to _____.

Options:
1) filter transformer oil
2) prevent ingress of moisture with air
3) the cooling oil
4) provide fresh air for increasing cooling effect

Answer: prevent ingress of moisture with air

Q 44 – The stator core of a synchronous machine is built up of ______ laminations.

Options:
1) stainless steel
2) silicon steel
3) cast iron
4) cast steel

Q 45 – The sag of a transmission line conductor in summer is _____.

Options:
1) less than that in winter
2) more than that in winter
3) same as in winter
4) None of these

Answer: more than that in winter

Q 46 – The slip rings employed in a 3-phase synchronous machine are insulated for _____.

Options:
1) output rated voltage
2) low voltage
3) very low voltage
4) very high voltage

Q 47 – For a linear electromagnetic circuit, which of the following statement is true?
Options:
1) Field energy is equal to the co-energy
2) Field energy is greater than the co-energy
3) Field energy is lesser than the co-energy
4) Co-energy is zero

Answer: Field energy is equal to the co-energy
Q 48 – A short circuited rectangular coil falls under gravity with the coil remaining in a vertical plane and cutting perpendicular horizontal magnetic lines of force. It has __________ acceleration.
Options:
1) zero
2) increasing
3) decreasing
4) constant

Q 49 – Reluctance torque in rotating machines is present, when _____.
Options:
1) air gap is not uniform
2) reluctance seen by stator mmf varies
3) reluctance seen by rotor mmf varies
4) reluctance seen by the working mmf varies

Answer: reluctance seen by the working mmf varies

Q 50 – In a dc motor the windage loss is proportional to _____.
Options:
1) supply voltage
2) square of the supply voltage
3) square of the flux density
4) square of the armature speed

Answer: square of the armature speed

SSC Junior Engineer Exam Paper – 2017 (https://www.newtondesk.com)

Q 51 – Generally the no-load losses of an electrical machine is represented in its equivalent circuit by a _____.
Options:
1) parallel resistance with a low value
2) series resistance with a low value
3) parallel resistance with a high value
4) series resistance with a high value

Answer: parallel resistance with a low value

Q 52 – The zero-suppression in recorders implies _____.
Options:
1) recording signals with reference to a point other than the zero
2) removing the static component so that rest of the signal is displayed with more expansion
3) providing inertia-less components to improve transient response
4) designing the recorder for zero error

Answer: removing the static component so that rest of the signal is displayed with more expansion

Q 53 – Null type recorders are __________ recorders.
Options:
1) potentiometric
2) bridge
3) LVDT
4) Any of these

Answer: Any of these

Q 54 – In a magnetic tape blanks are provided at the _____.
Options:
1) start of the tape
2) middle of the tape
3) end of the tape
4) start and end of the tape

Answer: start and end of the tape

Q 55 – If the number of bellows elements is made double and the thickness of the bellows element is made half, the displacement of the element for the same applied pressure would be the _____.
Options:
1) 16 times
2) 4 times
3) same
4) one-fourth

Q 56 – The meter measuring total flow in a liquid makes use of _____.
Options:
1) planimeter
2) variable area meter
3) square root extractor
4) none of these

Q 57 – Self-generating type transducers are __________ transducers.
Options:
1) active
2) passive
3) secondary
4) inverse

Q 58 – A transducer that converts measurand into the form of pulse is called the ___________ transducers.
Options:
1) active
2) analog
3) digital
4) pulse

Q 59 – High value pot resistance leads to _____.

Options:
1) low sensitivity
2) high sensitivity
3) low non-linearity
4) less error

Q 60 – In wire wound strain gauges, the change in resistance under strained condition is mainly on account of _____.
Options:
1) change in diameter of wire
2) change in the length of wire
3) change in both length and diameter of wire
4) change in resistivity

Answer: change in both length and diameter of wire

Q 61 – Which of the following is not an advantage of semiconductor gauges as compared to conventional strain gauges?
Options:
1) Excellent hysteresis characteristics
2) Least sensitive to temperature changes
3) High fatigue life
4) Smaller size

Answer: Least sensitive to temperature changes

Q 62 – In a vapour compression system, which of the following units is adversely affected by the presence of moisture?
Options:
1) evaporator
2) expansion valve
3) compressor
4) condenser

Q 63 – The range of horse power of diesel locomotive is _____.
Options:
1) 100 – 500
2) 1500 – 2500
3) 3000 – 4500
4) 4500 – 5000

Answer: 1500 – 2500

Q 64 – Electric traction in comparison to other traction systems has the advantages of _____.
Options:
1) higher acceleration and braking retardation
2) cleanest system and so ideally suitable for the underground and tube railways
3) better speed control
4) All of these

Answer: All of these

Q 65 – The method suitable for heating of conducting medium is _____.
Options:
1) Induction heating
2) Indirect arc heating
3) eddy current heating

Q 66 – The danger of electric shock is maximum _____.
Options:
1) before welding
2) during welding
3) while inserting electrode into the holder
4) after welding

Answer: while inserting electrode into the holder

Q 67 – Halogen lamps have the advantages of _____.
Options:
1) reduced dimensions of the lamp
2) better colour rendition and longer life (about 2000 hours)
3) high operating temperature with increased luminous efficiency
4) All of these

Answer: All of these

Q 68 – The primary reason for low power factor is owing to installation of _____.
Options:
1) synchronous motor
2) dc motors
3) induction motor
4) None of these

Q 69 – The load factor for domestic loads may be taken as _____.
Options:
2) 50 – 60%
3) 25 – 50%
4) 10 – 15%

Answer: 10 – 15%

Q 70 – An industrial consumer has a load pattern of 2000 kW 0.8 lag for 12 hours and 1000 kW unity power factor for 12 hours. The load factor is _____.
Options:
1) 0.5
2) 0.75
3) 0.6
4) 2

Q 71 – Diversity factor is the ratio of _____.
Options:
1) sum of maximum demands of consumers/system maximum demand
2) maximum demand of consumers/average demand
3) demand of all consumers/average demand
4) none of these

Answer: sum of maximum demands of consumers/system maximum demand

Q 72 – Diversity factor x maximum demand is _____.
Options:
1) average demand
2) sum of consumer’s maximum demands
3) installed capacity
4) generated capacity

Answer: sum of consumer’s maximum demands

Q 73 – As per recommendation of ISI the maximum number of points of lights, fans, and socket that can be connected in one sub-circuit is _____.
Options:
1) 8
2) 10
3) 15
4) 20

Q 74 – Which of the following wiring is preferred for workshop lighting?
Options:
1) casing-capping wiring
2) Batten wiring
3) Concealed conduit wiring
4) Surface conduit wiring

Answer: Concealed conduit wiring

Q 75 – According to fuse law, the current carrying capacity varies as _____.
Options:
1) diameter
2) (diameter)1.5
3) (diameter)1/2
4) 1/(diameter)

SSC Junior Engineer Exam Paper – 2017 (https://www.newtondesk.com)

Q 76 – The loop earth wire used shall not be of size less than _____.
Options:
1) 8 SWG
2) 10 SWG
3) 20 SWG
4) 14 SWG (2.9 mm2) or half of the size of the sub-circuit wireQ

Answer: 14 SWG (2.9 mm2) or half of the size of the sub-circuit wireQ

Q 77 – Third pin in a 3-pin plug is provided so as to _____.
Options:
1) provide an earth connection
2) provide a 3-phase supply, when required
3) provide a spare phase when required
4) prevent the plug being reversed in the socket

Answer: provide an earth connection

Q 78 – Which one of the following is used as an active device in electronic circuits?
Options:
1) Transformer
2) Electric heater
3) SCR
4) Loudspeaker

Q 79 – A device having characteristics very close to that of an ideal voltage source is _____.
Options:
1) Vacuum diode
2) Zener diode
3) Transistor
4) FET

Q 80 – For thermionic emission _____.
Options:
1) a material with high work function is preferable
2) a material with low work function is preferable
3) the work function of the material has no importance
4) None of these

Answer: a material with low work function is preferable

Q 81 – A photocell is illuminated by a small bright source placed 1 m away. When the same source of light is placed two metres away, the electrons emitted by the photocathode _____.
Options:
1) each carry one quarter of their previous energy
2) each carry one quarter of their previous moments
3) are half as numerous
4) are one-quarter as numerous

Answer: are one-quarter as numerous

Q 82 – In a vacuum tetrode secondary emission is because of emission of _____.
Options:
1) electrons from the filament due to heat energy
2) high velocity electrons from the cathode
3) electrons from the plate due to bombardment of the fast moving electrons emitted from the cathode
4) electrons belonging to the second orbit of the atoms of cathode

Answer: electrons from the plate due to bombardment of the fast moving electrons emitted from the cathode

Q 83 – Which of the following circuit is mostly used as an amplifier?
Options:
1) common base circuit because it has high voltage gain
2) common emitter circuit because it has high voltage and current gain
3) common collector circuit because it has high gain
4) common emitter circuit is of a little use because it has extremely low input resistance

Answer: common emitter circuit because it has high voltage and current gain

Q 84 – In a dc compound motor, 4-point starter provided as _____.
Options:
1) to reduce the field current
2) to increase the field current
3) not to affect the current flowing through ‘Hold on’ coil even when the field current changes
4) none of these

Answer: not to affect the current flowing through ‘Hold on’ coil even when the field current changes

Q 85 – The simplest form of a motor controller is _____.
Options:
1) relay
2) toggle switch
3) drum switch
4) magnetic switch

Q 86 – The plugging provides ___________ braking torque in comparison to rheostatic and regenerative braking systems.
Options:
1) negligible
2) small
3) highest
4) None of these

Q 87 – Dynamic braking is very effective if the dc motor _____.
Options:
1) is series excited
2) is shunt excited
3) is separately excited
4) has cumulative compound excitation

Answer: is separately excited

Q 88 – In case of dc shunt motors, the regenerative braking is employed when the load _____.
Options:
1) has an overhauling characteristic
2) is variable
3) is constant
4) also acts as braking force

Answer: has an overhauling characteristic

Q 89 – The variable loss in a dc shunt machine is _____.
Options:
1) iron loss
2) shunt field loss
3) armature copper loss
4) friction and windage loss

Answer: armature copper loss

Q 90 – In a synchronous generator, a divided winding rotor is preferable to a conventional winding rotor because of _____.
Options:
1) higher efficiency
2) increased steady-state stability limit
3) higher short circuit ration
4) better damping

Q 91 – The stator winding of an alternator is normally connected in star to eliminate the _________ harmonic component of the voltage waveform.
Options:
1) third
2) fifth
3) seventh
4) None of these

Q 92 – How can the reactive power delivered by a synchronous generator be controlled?
Options:
1) by changing the prime mover input
2) by changing the excitation
3) by changing the direction of rotation
4) by changing the prime mover speed

Answer: by changing the excitation

Q 93 – The armature reaction effect in a synchronous machine depends on _____.
Options:
2) power factor of the load
3) speed of the machine
4) both load current and power factor of the load

Answer: both load current and power factor of the load

Q 94 – A synchronous generator is feeding a zero power factor (lagging) load at rated current. The armature reaction is _____.
Options:
1) magnetizing
2) demagnetizing
3) cross-magnetizing
4) ineffective

Q 95 – A synchronous motor may fail to pull into synchronism owing to _____.
Options:
2) low excitation
3) high friction
4) Any of the options

Answer: Any of the options

Q 96 – The rated voltage of a 3-phase power system is given as _____.
Options:
1) rms phase voltage
2) peak phase voltage
3) rms line to line voltage
4) peak line to line voltage

Answer: rms line to line voltage

Q 97 – Feeder is designed mainly from the point of view of _____.
Options:
1) its current carrying capacity
2) voltage drop in it
3) operating voltage
4) operating frequency

Answer: its current carrying capacity

Q 98 – 66 kV is suitable for transmission of power over _____.
Options:
1) 30 km
2) 60 km
3) 120 km
4) 200 km

Q 99 – Which of the following properties has got higher value for aluminium in comparison to that of copper?
Options:
1) Electrical resistivity
2) Melting point
3) Thermal conductivity
4) Specific gravity

Q 100 – ACSR conductors have _____.
Options:
1) all conductors made of aluminium
2) outer conductors made of aluminum
3) inner conductors made of aluminum
4) no conductors made of aluminum