(Papers) SSC Junior Engineer Exam Paper - 2016 "held on 04
March 2017 "Afternoon Shift( General Engineering)
QID : 601 - A current is said to be alternating when it changes in _____.
1) Magnitude only
2) Direction only
3) Both magnitude and direction
4) None of these
Correct Answer: Both magnitude and direction
QID : 602 - The rms value of a sine wave is 100 A. Its peak value is _____.
1) 70.7 A
2) 141.4 A
3) 150 A
4) 282.8 A
Correct Answer: 141.4 A
QID : 603 - 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 _____.
2) 1.11 V1/V2
3) 2 V1/V2
4) π V1/2V2
Correct Answer: 1.11 V1/V2
QID : 604 - 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 _____.
1) 14.1 A
2) 17.3 A
3) 22.4 A
4) 30 A
Correct Answer: 17.3 A
QID : 605 - 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 _____.
Correct Answer: 75
QID : 606 - Which of the following statements pertains to resistor only?
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
Correct Answer: they can dissipate desirable amount of power
QID : 607 -
1) 7.29 W
2) 52.4 W
3) 135 W
4) 270 W
Correct Answer: 270 W
QID : 608 - Purely inductive circuit takes power from the ac mains when _____.
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
Correct Answer: applied voltage decreases but current increases
QID : 609 - A pure capacitance connected across 50 Hz, 230 V supply consumes 0.04 W. This consumption is attributed to _____.
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
Correct Answer: Both ohmic loss due to ohmic resistance of plates and loss of energy in dielectric
QID : 610 - 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 _____.
Correct Answer: ?0104cos103t
QID : 611 -
1) 0.5 H
2) 0.6 H
3) 1 H
4) 1.5 H
Correct Answer: 1.5 H
QID : 612 -
QID : 613 - 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 _____.
Correct Answer: 36°
QID : 614 - 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 _____.
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
Correct Answer: 10 W and 17.32 VAR
QID : 615 - In an RLC circuit, supplied from an ac source, the reactive power is proportional to the
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
Correct Answer: difference between the average energy stored in the electric field and that stored in the magnetic field
QID : 616 - In gases the flow of current is due to _____.
1) Electrons only
2) Positive and negative ions
3) Electrons, positive ions
4) Electrons, positive ions and negative ions
Correct Answer: Electrons, positive ions and negative ions
QID : 617 - Ohm's law is applicable to _____.
2) vacuum tubes
4) None of these
Correct Answer: None of these
QID : 618 - Pure metals generally have _____.
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
Correct Answer: high conductivity and large temperature coefficient
QID : 619 - 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 _____.
1) 1 MΩ
2) 10 MΩ
3) 0.1 MΩ
4) 0.01 MΩ
Correct Answer: 0.1 MΩ
QID : 620 -
1) 1/15 A
2) 2/15 A
3) 4/15 A
4) 8/15 A
Correct Answer: 8/15 A
QID : 621 - Which of the following does not use heating effect of electric current?
1) Electric furnace
3) Electric iron
4) Vacuum cleaner
Correct Answer: Vacuum cleaner
QID : 622 -
1) 2.5 Ω
2) 5 Ω
3) 7.5 Ω
4) 10 Ω
Correct Answer: 7.5 Ω
QID : 623 - Four 100 W bulbs are connected in parallel across 200 V supply line. If one bulb gets fused _____.
1) no bulb will light
2) all the four bulbs will light
3) rest of the three bulbs will light
4) None of these
Correct Answer: rest of the three bulbs will light
QID : 624 - A 100 watt light bulb burns on an average of 10 hours a day for one week. The weekly consumption of energy will be _____.
1) 7 units
2) 70 units
3) 0.7 units
4) 0.07 units
Correct Answer: 7 units
QID : 625 - The elements which are not capable of delivering energy by its own are known as _____.
1) unilateral elements
2) nonlinear elements
3) passive elements
4) active elements
Correct Answer: passive elements
QID : 626 - A network has 4 nodes and 3 independent loops. What is the number of branches in the network?
Correct Answer: 6
QID : 627 - A connected network of N > 2 nodes has at most one branch directly connecting any pair of nodes. The graph of the network _____.
N > 2 नोड्स के जुड़े नेटवर्क में किसी भी निस्पंद (नोड्स) के जोड़ो को सीधे मिलाने के लिए न्यूनतम एक शाखा होती है। नेटवर्क के ग्राफ में ________
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
Correct Answer: must have at least N branches for one or more closed paths to exist
QID : 628 -
Correct Answer: 1
QID : 629 - Ideal voltage source have _____.
1) zero internal resistance
2) infinite internal resistance
3) low value of current
4) large value of emf
Correct Answer: zero internal resistance
QID : 630 - A voltage source having an open circuit voltage of 100 V and internal resistance of 50 Ω is equivalent to a current source _____.
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
Correct Answer: 2 A in parallel with 50 Ω
QID : 631 -
1) 96 W
2) 114 W
3) 192 W
4) 288 W
Correct Answer: 288 W
QID : 632 -
1) IR + E
2) E – IR
3) 2IR – (E/2)
4) (E/2) – IR
Correct Answer: (E/2) – IR
QID : 633 - 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 _____.
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
Correct Answer: is half of the previous value
QID : 634 - 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.
1) 2100 AT
2) 1671 AT
3) 1447 AT
4) 167 AT
Correct Answer: 1671 AT
QID : 635 - An air gap is usually inserted in magnetic circuits so as to _____.
1) prevent saturation
2) increase mmf
3) increase in flux
4) increase in inductance
Correct Answer: prevent saturation
QID : 636 - Which of the following statements is correct?
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
Correct Answer: The magnetic flux inside the exciting coil is the same as on its outer surface
QID : 637 - 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 _____.
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
Correct Answer: A, B and C are correct
QID : 638 - 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 _____.
1) 60 V
2) 40 V
3) 80 V
4) 8 V
Correct Answer: 40 V
QID : 639 - According to Faraday's law of electromagnetic induction an emf is induced in a conductor whenever it _____.
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
Correct Answer: cuts the magnetic flux
QID : 640 - "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 _____.
1) Lenz's law
2) Faraday's law of magnetic induction
3) Fleming's law of induction
4) Ampere's law
Correct Answer: Lenz's law
QID : 641 - 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?
1) 250 KVA
2) 500 kVA
3) 1000 kVA
4) 125 kVA
Correct Answer: 250 KVA
QID : 642 - The all day efficiency of a transformer depends primarily on _____.
1) its copper losses
2) the amount of load
3) the duration of load
4) Both the amount and duration of load
Correct Answer: Both the amount and duration of load
QID : 643 - In a power transformer, the breather is provided in order to _____.
1) filter transformer oil
2) prevent ingress of moisture with air
3) the cooling oil
4) provide fresh air for increasing cooling effect
Correct Answer: prevent ingress of moisture with air
QID : 644 - The stator core of a synchronous machine is built up of ______ laminations.
1) stainless steel
2) silicon steel
3) cast iron
4) cast steel
Correct Answer: silicon steel
QID : 645 - The sag of a transmission line conductor in summer is _____.
1) less than that in winter
2) more than that in winter
3) same as in winter
4) None of these
Correct Answer: more than that in winter
QID : 646 - The slip rings employed in a 3-phase synchronous machine are insulated for _____.
1) output rated voltage
2) low voltage
3) very low voltage
4) very high voltage
Correct Answer: low voltage
QID : 647 - For a linear electromagnetic circuit, which of the following statement is true?
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
Correct Answer: Field energy is equal to the co-energy
QID : 648 - 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.
Correct Answer: constant
QID : 649 - Reluctance torque in rotating machines is present, when _____.
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
Correct Answer: reluctance seen by the working mmf varies
QID : 650 - In a dc motor the windage loss is proportional to _____.
1) supply voltage
2) square of the supply voltage
3) square of the flux density
4) square of the armature speed
Correct Answer: square of the armature speed
QID : 651 - Generally the no-load losses of an electrical machine is represented in its equivalent circuit by a _____.
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
Correct Answer: parallel resistance with a low value
QID : 652 - The zero-suppression in recorders implies _____.
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
Correct Answer: removing the static component so that rest of the signal is displayed with more expansion
QID : 653 - Null type recorders are __________ recorders.
4) Any of these
Correct Answer: Any of these
QID : 654 - In a magnetic tape blanks are provided at the _____.
1) start of the tape
2) middle of the tape
3) end of the tape
4) start and end of the tape
Correct Answer: start and end of the tape
QID : 655 - 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 _____.
1) 16 times
2) 4 times
Correct Answer: 16 times
QID : 656 - The meter measuring total flow in a liquid makes use of _____.
2) variable area meter
3) square root extractor
4) none of these
Correct Answer: planimeter
QID : 657 - Self-generating type transducers are __________ transducers.
Correct Answer: active
QID : 658 - A transducer that converts measurand into the form of pulse is called the ___________ transducers.
Correct Answer: digital
QID : 659 - High value pot resistance leads to _____.
1) low sensitivity
2) high sensitivity
3) low non-linearity
4) less error
Correct Answer: high sensitivity
QID : 660 - In wire wound strain gauges, the change in resistance under strained condition is mainly on account of _____.
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
Correct Answer: change in both length and diameter of wire
QID : 661 - Which of the following is not an advantage of semiconductor gauges as compared to conventional strain gauges?
1) Excellent hysteresis characteristics
2) Least sensitive to temperature changes
3) High fatigue life
4) Smaller size
Correct Answer: Least sensitive to temperature changes
QID : 662 - In a vapour compression system, which of the following units is adversely affected by the presence of moisture?
2) expansion valve
Correct Answer: expansion valve
QID : 663 - The range of horse power of diesel locomotive is _____.
1) 100 – 500
2) 1500 – 2500
3) 3000 – 4500
4) 4500 – 5000
Correct Answer: 1500 – 2500
QID : 664 - Electric traction in comparison to other traction systems has the advantages of _____.
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
Correct Answer: All of these
QID : 665 - The method suitable for heating of conducting medium is _____.
1) Induction heating
2) Indirect arc heating
3) eddy current heating
4) radiant heating
Correct Answer: Induction heating
QID : 666 - The danger of electric shock is maximum _____.
1) before welding
2) during welding
3) while inserting electrode into the holder
4) after welding
Correct Answer: while inserting electrode into the holder
QID : 667 - Halogen lamps have the advantages of _____.
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
Correct Answer: All of these
QID : 668 - The primary reason for low power factor is owing to installation of _____.
1) synchronous motor
2) dc motors
3) induction motor
4) None of these
Correct Answer: induction motor
QID : 669 - The load factor for domestic loads may be taken as _____.
1) about 85%
2) 50 – 60%
3) 25 – 50%
4) 10 – 15%
Correct Answer: 10 – 15%
QID : 670 - 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 _____.
Correct Answer: 0.6
QID : 671 - Diversity factor is the ratio of _____.
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
Correct Answer: sum of maximum demands of consumers/system maximum demand
QID : 672 - Diversity factor x maximum demand is _____.
1) average demand
2) sum of consumer's maximum demands
3) installed capacity
4) generated capacity
Correct Answer: sum of consumer's maximum demands
QID : 673 - As per recommendation of ISI the maximum number of points of lights, fans, and socket that can be connected in one sub-circuit is _____.
Correct Answer: 10
QID : 674 - Which of the following wiring is preferred for workshop lighting?
1) casing-capping wiring
2) Batten wiring
3) Concealed conduit wiring
4) Surface conduit wiring
Correct Answer: Concealed conduit wiring
QID : 675 - According to fuse law, the current carrying capacity varies as _____.
Correct Answer: (diameter)1.5
QID : 676 - The loop earth wire used shall not be of size less than _____.
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
Correct Answer: 14 SWG (2.9 mm2) or half of the size of the sub-circuit wireQ
QID : 677 - Third pin in a 3-pin plug is provided so as to _____.
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
Correct Answer: provide an earth connection
QID : 678 - Which one of the following is used as an active device in electronic circuits?
2) Electric heater
Correct Answer: SCR
QID : 679 - A device having characteristics very close to that of an ideal voltage source is _____.
1) Vacuum diode
2) Zener diode
Correct Answer: Zener diode
QID : 680 - For thermionic emission _____.
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
Correct Answer: a material with low work function is preferable
QID : 681 - 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 _____.
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
Correct Answer: are one-quarter as numerous
QID : 682 - In a vacuum tetrode secondary emission is because of emission of _____.
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
Correct Answer: electrons from the plate due to bombardment of the fast moving electrons emitted from the cathode
QID : 683 - Which of the following circuit is mostly used as an amplifier?
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
Correct Answer: common emitter circuit because it has high voltage and current gain
QID : 684 - In a dc compound motor, 4-point starter provided as _____.
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
Correct Answer: not to affect the current flowing through 'Hold on' coil even when the field current changes
QID : 685 - The simplest form of a motor controller is _____.
2) toggle switch
3) drum switch
4) magnetic switch
Correct Answer: toggle switch
QID : 686 - The plugging provides ___________ braking torque in comparison to rheostatic and regenerative braking systems.
4) None of these
Correct Answer: highest
QID : 687 - Dynamic braking is very effective if the dc motor _____.
1) is series excited
2) is shunt excited
3) is separately excited
4) has cumulative compound excitation
Correct Answer: is separately excited
QID : 688 - In case of dc shunt motors, the regenerative braking is employed when the load _____.
1) has an overhauling characteristic
2) is variable
3) is constant
4) also acts as braking force
Correct Answer: has an overhauling characteristic
QID : 689 - The variable loss in a dc shunt machine is _____.
1) iron loss
2) shunt field loss
3) armature copper loss
4) friction and windage loss
Correct Answer: armature copper loss
QID : 690 - In a synchronous generator, a divided winding rotor is preferable to a conventional winding rotor because of _____.
1) higher efficiency
2) increased steady-state stability limit
3) higher short circuit ration
4) better damping
Correct Answer: increased steady-state stability limit
QID : 691 - The stator winding of an alternator is normally connected in star to eliminate the _________ harmonic component of the voltage waveform.
4) None of these
Correct Answer: third
QID : 692 - How can the reactive power delivered by a synchronous generator be controlled?
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
Correct Answer: by changing the excitation
QID : 693 - The armature reaction effect in a synchronous machine depends on _____.
1) load current
2) power factor of the load
3) speed of the machine
4) both load current and power factor of the load
Correct Answer: both load current and power factor of the load
QID : 694 - A synchronous generator is feeding a zero power factor (lagging) load at rated current. The armature reaction is _____.
Correct Answer: demagnetizing
QID : 695 - A synchronous motor may fail to pull into synchronism owing to _____.
1) excessive load
2) low excitation
3) high friction
4) Any of the options
Correct Answer: Any of the options
QID : 696 - The rated voltage of a 3-phase power system is given as _____.
1) rms phase voltage
2) peak phase voltage
3) rms line to line voltage
4) peak line to line voltage
Correct Answer: rms line to line voltage
QID : 697 - Feeder is designed mainly from the point of view of _____.
1) its current carrying capacity
2) voltage drop in it
3) operating voltage
4) operating frequency
Correct Answer: its current carrying capacity
QID : 698 - 66 kV is suitable for transmission of power over _____.
1) 30 km
2) 60 km
3) 120 km
4) 200 km
Correct Answer: 60 km
QID : 699 - Which of the following properties has got higher value for aluminium in comparison to that of copper?
1) Electrical resistivity
2) Melting point
3) Thermal conductivity
4) Specific gravity
Correct Answer: Electrical resistivity
QID : 700 - ACSR conductors have _____.
1) all conductors made of aluminium
2) outer conductors made of aluminum
3) inner conductors made of aluminum
4) no conductors made of aluminum
Correct Answer: outer conductors made of aluminum