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Objective Questions

Latest IOCL Southern Region Junior Operator Exam Question (Objective Questions), MCQ in English

Subjects : Electrical, English, Reasoning, mathematics

Question Bank IOCL Southern Region Junior Operator Exam (Electrical) - English
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Electrical

Question 1Single Answer
When a very small amount of higher conducting metal is added to a conductor, its conductivity will 
  1. A
    increase
  2. B
     decrease
  3. C
    remain the same 
  4. D
    increase or decrease depending on the impurity
Question 2Single Answer
An electrically balanced atom has 30 protons in its nucleus and 2 electrons in its outermost shell. The materials made of such atom is
  1. A
    a conductor
  2. B
    an insulator
  3. C
    a semiconductor 
  4. D
    a superconductor
Question 3Single Answer
The temperature coefficient of resistance of a doped semiconductor is
  1. A
    always positive
  2. B
    always negative
  3. C
    zero 
  4. D
    positive or negative depending upon the level of doping 
Question 4Single Answer
In the slice processing of an integrated circuit
  1. A
    components are formed in the areas where silicon dioxide remains
  2. B
    components are formed in the areas where silicon dioxide has been removed
  3. C
    the diffusing elements diffuse through silicon dioxide 
  4. D
    only on diffusion process is used 
Question 5Single Answer
Permanent magnet loses the magnetic behaviour when heated because of
1. atomic vibration
2. dipole vibration
3. realignment of dipoles
Which of the above are correct?
  1. A
    1  and 2 only 
  2. B
    1 and 3 only
  3. C
    1, 2 and 3         
  4. D
    2 and 3
Question 6Single Answer
A Zener regulator has an input voltage varying between 20 V and 30 V. The desired regulated voltage is 12 V, while the load varies between 140  and 10k  The maximum resistance in series with the unregulated source and Zener diode would be
  1. A
    3.3
  2. B
    6.6
  3. C
    36.6
  4. D
    93.3
Question 7Single Answer
A short in any type of circuit (series, parallel or combination) causes the total circuit
1. resistance to decrease
2. power to decreases
3. current to increase
Which of the above are correct?
  1. A
    2  and 3 
  2. B
    2 and 4
  3. C
    1 and 4 
  4. D
    1 and 3 
Question 8Single Answer
An air-cored solenoid of 250 turns has a cross-sectional area A = 80 cm2 and length l = 100 cm. The value of its inductance is
  1. A
    0.425 mH          
  2. B
    0.628 mH
  3. C
    0.751 mH 
  4. D
    0.904 mH
Question 9Single Answer
The current in a coil changes uniformly from 10 A to 1 A in half a second. A voltmeter connected across the coil gives a reading of 36 V. The self-inductance of the coil is
  1. A
    0.5 H 
  2. B
    1 H
  3. C
    2 H       
  4. D
    4 H 
Question 10Single Answer
In a mutually coupled circuit, the primary current is reduced from 4A to zero in 10 s.  A voltage of 40000 V is observed across the secondary. The mutual inductance between the coils is
  1. A
    100 H 
  2. B
    10 H
  3. C
    0.1 H 
  4. D
    0.01 H 
Question 11Single Answer
A CRO screen has 10 divisions on the horizontal scale. If a voltage signal 5 sin (314t + 45°) is examined with a line base setting of 5 ms/div, the number of signals displayed on the screen will be 
  1. A
    1.25 cycles           
  2. B
    2.5 cycles 
  3. C
    5 cycles 
  4. D
    10 cycles 
Question 12Single Answer
Which one of the following conditions will be correct when three identical bulbs forming a star are connected to a three-phase balanced supply?
 
  1. A
    The bulb in R phase will be the brightest 
  2. B
    The bulb in Y phase will be the brightest 
  3. C
    The bulb in B phase will be the brightest 
  4. D
    All the bulbs will be equally bright 
Question 13Single Answer
Loading by the measuring instruments introduces an error in the measured parameter. Which of the following devices gives most accurate result?
  1. A
    PMMC
  2. B
    Hot-wire
  3. C
    CRO 
  4. D
    Electrodynamic
Question 14Single Answer
A moving-coil galvanometer can be used as a DC ammeter by connecting
  1. A
    a high resistance in series with the meter
  2. B
    a high resistance across the meter
  3. C
    a low resistance across the meter
  4. D
    a low resistance in series with the meter
Question 15Single Answer
Consider the following types of damping:
1. Air-friction damping
2.Fluid-friction damping
3.Eddy-current damping
PMMC type instruments use which of the above?
  1. A
    1 only   
  2. B
    2 only
  3. C
    3 only 
  4. D
    1,2 and 3
Question 16Single Answer
In data acquisition system, analog data acquisition system is used
  1. A
    for narrow frequency width, while digital data acquisition system is used when wide frequency width is to be monitored
  2. B
    for wide frequency width, while digital data acquisition system is used when narrow frequency width is to be monitored
  3. C
    when quantity to be monitored varies slowly, while its counterpart is preferred if the quantity to be monitored varies very fast
  4. D
    when quantity to be monitored is time-variant, while digital data acquisition system is preferred when quantity is time invariant
Question 17Single Answer
During the measurement of resistance by Carey Foster bridge, no error is introduced due to
1.contact resistance
2. Connecting leads
3.thermoelectric e.m.f.
which of the above are correct?
  1. A
    1 and 2 only 
  2. B
    1 and 3 only
  3. C
    2 and 3 only 
  4. D
    1,2 and 3
Question 18Single Answer
Which of the following is true for the complete response of any network voltage or current variables for a step excitation to a first-order circuit?
  1. A
    It has the form at k1 e-at
  2. B
    It has the form k 
  3. C
    It may have either the form (a) or the form of (a) plus (b) 
  4. D
    It has the form e+at
Question 19Single Answer
A piezoelectric crystal has a coupling coefficient K of 0.32. How much electrical energy must be applied to produce output energy of 7.06 × 10–3 J?
  1. A
    25.38 mJ 
  2. B
    22.19 mJ 
  3. C
    4.80 mJ 
  4. D
    2.26 mJ 
Question 20Single Answer
A wattmeter reads 10 kW, when its current coil is connected in R phase and the potential coil is connected across R and neutral of a balanced 400 V (RYB sequence) supply. The line current is 54 A. If the potential coil reconnected across B-Y phases with the current coil in R phase, the new reading of the wattmeter will be nearly
  1. A
    10 kW 
  2. B
    13 kW
  3. C
    16 kW 
  4. D
    19 kW 
Question 21Single Answer
For a type-I system, the intersection of the initial slope of the Bode plot with 0dB axis gives
  1. A
    steady-state error
  2. B
    error constant
  3. C
    phase margin
  4. D
    cross-over frequency
Question 22Single Answer
The desirable features of a servomotor are
  1. A
    low rotor inertia and low bearing friction
  2. B
    high rotor inertia and high bearing friction.
  3. C
    low rotor inertia and high bearing friction
  4. D
    high rotor inertia low bearing friction
Question 23Single Answer
Permeance is inversely related to
  1. A
    resistance 
  2. B
    conductance
  3. C
    reluctance         
  4. D
    capacitance
Question 24Single Answer
Consider the following statements regarding an ideal core material:
1. It has very high permeability.
2. It loses all its magnetism when there is no current flow.
3. It does not saturate easily.
Which of the above statements are correct?
  1. A
    1 and 2 only 
  2. B
    1 and 3 only
  3. C
    2 and 3 only 
  4. D
    1, 2 and 3
Question 25Single Answer
The characteristic impedance of a transmission line depends upon
  1. A
    shape of the conductor
  2. B
    surface treatment of the conductor
  3. C
    conductivity of the material 
  4. D
    geometric configuration of the conductor
Question 26Single Answer
Superconductivity in a material can be destroyed by
1. increasing the temperature above a certain limit.
2. applying a magnetic field above a certain limit.
3. passing a current above a certain limit.
4. decreasing the temperature to a point below the critical temperature
Which of the above are correct?
  1. A
    1  and 2 only 
  2. B
    2 and 3 only
  3. C
    1, 2 and 3 only 
  4. D
    1, 2, 3 and 4
Question 27Single Answer
The electrical resistivity of many metals and alloys drops suddenly to zero when they are current of 5 A at an angle of 30° lagging. The readings of the two wattmeters W1 and W2 used for measuring the power drawn by the circuit, are respectively
  1. A
    2000 W and 1000 W  
  2. B
    1500 W and 1500 W  
  3. C
    2000 W and 1500 W 
  4. D
    1500 W and 1000 W 
Question 28Single Answer
The mesh current method
1. works with both planner and non planar circuits
2. uses Kirchhoff’s voltage law
which of the above is/are correct? 
  1. A
    1 only 
  2. B
    2 only 
  3. C
    Both 1 and 2 
  4. D
    Neither 1 nor 2
     
Question 29Single Answer
When gain K of the open loop transfer function of order greater than unity is varied from zero to infinity, the closed loop system.
  1. A
    may become unstable 
  2. B
    stability may improve 
  3. C
    stability may not be affected 
  4. D
    will become highly stable 
Question 30Single Answer
Consider the following statements:
1. Adding a zero to the G(s)H(s) tends to push root locus to the left.
2. Adding a pole to the G(s)H(s) tends to push root locus to the right.
3. Complementary root locus (CRL) refers to root loci with positive K.
4. Adding a zero to the forward path transfer function reduces the maximum overshoot of the system.
Which of the above statements are correct? 
  1. A
    1,2 and 3 only 
  2. B
    3 and 4 only 
  3. C
    1, 2 and 4 only 
  4. D
    1, 2, 3 and 4
     
Question 31Single Answer
The magnetic field required to reduce the residual magnetization to zero is called
  1. A
    retentivity
  2. B
    coercivit
  3. C
    hysteresis 
  4. D
    saturation
Question 32Single Answer
A certain fluxmeter has the following specifications:
Air gap flux density = 0.05 Wb/m2
Number of turns on moving coil = 40
Area of moving coil = 750 mm2
If the flux linking 10 turns of a search coil of 200 mm2 area connected to the fluxmeter is reversed in a uniform field of 0.5 Wb/m2, then the deflection of the fluxmeter will be
  1. A
    87.4° 
  2. B
    76.5°
  3. C
    65.6° 
  4. D
    54.7° 
Question 33Single Answer
Consider the following statements:
1. Both ferromagnetic and ferrimagnetic materials have domain structures; each domain has randomly oriented magnetic moments when no external field is applied.
2. Both ferromagnetic and ferrimagnetic
materials make those domains that have favourable orientation to the applied field grow in size.
3. The net magnetic moment in ferromagnetic materials is higher than that in ferrimagnetic materials.
4. The net magnetic moment in ferrimagnetic materials is higher than that in ferromagnetic material.
Which of the above statements are correct?
  1. A
    1  and 4 only 
  2. B
    1, 2 and 4
  3. C
    2 and 4 only 
  4. D
    1, 2 and 3
Question 34Single Answer
Two bulbs of 100 W/250 V and 150 W/250 V are connected in series across a supply of 250 V. The power consumed by the circuit is
  1. A
    30 W
  2. B
    60 W
  3. C
    100 W 
  4. D
    250 W
Question 35Single Answer
Two -wattmeter method of power measurement in three-phase system is valid for
  1. A
    balanced star-connected load only
  2. B
    unbalanced star-connected load only 
  3. C
    balanced delta-connected load only 
  4. D
    balanced or unbalanced star as well as delta-connected loads 
Question 36Single Answer
Schering bridge is a very versatile AC bridge and is used for capacitor testing in terms of
1. capacitance value (magnitude)
2. loss angle measurement
3. simple balance detector like PMMC instrument
4. Providing safety to operators by incorporating Wagner earthing device
Which of the above are correct?
  1. A
    1 and 3 only 
  2. B
    3 and 4 only 
  3. C
    1, 2 and 4 only 
  4. D
    1, 2, 3 and 4
Question 37Single Answer
Consider the following instruments:
1. MI instrument
2. Electrostatic instrument
3. Electrodynamometer instrument
which of the above instruments is/are free from hysteresis and eddy-current losses?
  1. A
    1 only 
  2. B
    2 only 
  3. C
    3 only 
  4. D
    1, 2 and 3
Question 38Single Answer
Dummy strain gauges are used for
  1. A
    compensation of temperature changes 
  2. B
    increasing the sensitivity of bridge 
  3. C
    compensating for different expansions
  4. D
    calibration of strain gauge 
Question 39Single Answer
Analog-to-digital convertor with the minimum number of bits that will convert analog input signals in the range of 0–5 V to an accuracy of 10 mV is
  1. A
    6
  2. B
    9
  3. C
    12 
  4. D
    15 
Question 40Single Answer
What should be done to find the initial values of the circuit variables in a first-order R-C circuit excited by only initial conditions?
  1. A
    To replace the capacitor by a short circuit 
  2. B
    To replace the capacitor by an open circuit 
  3. C
    To replace the capacitor by a voltage source 
  4. D
    To replace the capacitor by a current source 

English

Question 41Single Answer
I go to Madurai by —– Vaigai Express
  1. A
    a
  2. B
    an
  3. C
    some
  4. D
    the
Question 42Single Answer
Have the car stolen!
  1. A
    Steal the car
  2. B
    You should have the stolen car
  3. C
    Get someone to steal the car
  4. D
    They have stolen the car
Question 43Single Answer
The payment was collected by the hardworking salesman.
  1. A
    The hardworking salesman collected the payment.
  2. B
    the salesman who worked heard was able to collect the payment.
  3. C
    to collect the payment the salesman had to work hard.
  4. D
    The hardworking salesman was able to collect the payment.
Question 44Single Answer
I had to stop all my work to complete this project.
  1. A
    All other work had to be stopped to complete this project by me
  2. B
    For completing this project all other work must be stopped
  3. C
    For completing this project I had to stop all my work
  4. D
    To complete this project all other work had been stopped by me
Question 45Single Answer
They have published the names of all the successful candidates.
  1. A
    The candidates who have succeeded their names they had published.
  2. B
    The names of all the successful candidates have been published by them
  3. C
    The candidates who have succeeded their names have been published by them.
  4. D
    The names of all the successful candidate were published by them. 
Question 46Single Answer
The online shopping site lowered the prices.
  1. A
    Lowering of the prices was done by the online shopping site
  2. B
    The prices were lowered by the online shopping site
  3. C
    The prices had been lowered by the online shopping site
  4. D
    The prices have been lowered by the online shopping site
Question 47Single Answer
Who taught you to drive a truck ?
  1. A
    To drive a truck by whom were you taught?
  2. B
    Driving a truck by who were you taught?
  3. C
    Driving a truck by who were you being taught?
  4. D
    By whom were you taught to drive a truck?
Question 48Single Answer
We shall invite Suresh.
  1. A
    Suresh would be invited by us
  2. B
    Suresh would have been invited by us
  3. C
    Suresh will be invited by us
  4. D
    Suresh will have been invited by us
Question 49Single Answer
Dark clouds have overcast the evening sky.
  1. A
    By the dark clouds the evening sky was overcast.
  2. B
    The evening sky has been overcast by the dark clouds.
  3. C
    Dark clouds overcastted the evening sky.
  4. D
    The sky of the evening was overcasted by dark clouds.
Question 50Single Answer
The partners will celebrate their triumph tomorrow. 
  1. A
    The triumph would be celebrated by the partners a day before
  2. B
    The triumph would be celebrated by the partners a day after
  3. C
    The triumph would have been celebrated by the partners a day after
  4. D
    The triumph will have been celebrated by the partners tomorrow
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