# Basic Electrical Engineering Expected MCQ PDF2 For Coal India Limited (CIL) MT Exam 2017

1)   In half wave rectifiers, diode conducts during
a. Only positive half cycle
b. Only negative half cycle
c. Both positive and negative half cycle
d. Neither in positive half cycle nor in negative half cycle

2)   Specific resistance of a material is
a. Directly proportional to the both area of cross section and length of material
b. Directly proportional to the area of cross section and inversely proportional to the length of material
c. Inversely proportional to the area of cross section and directly proportional to the length of material
d. Inversely proportional to the both area of cross section and length of material

 ANSWER: Directly proportional to the area of cross section and inversely proportional to the length of material
3)   One coulomb of charge is equal to the charge of
a. 1.095 x 10 –19 electrons
b. 1.625 x 10–31 electrons
c. 6.242 x 1018 electrons
d. 6.025 x 10–19 electrons

4)   Which among the following is true about ohm’s law?
a. I ∝ V
b. I = V/R
c. V = IR
d. All of these

5)   In any network of wires carrying currents, the algebraic sum of all currents meeting at a point is equal to
a. Sum of all the currents
b. Zero
c. Sum of outgoing current
d. Sum of incoming current

6)   Electrical appliances which works on the electromagnetic principle is / are

a. Generators
b. Motors
c. Transformers
d. All of these

7)   The materials with permeability less than unity are called
a. Diamagnetic materials
b. Paramagnetic materials
c. Ferromagnetic materials
d. Anti ferromagnetic materials

8)   The magnetic materials which are strongly attracted by the magnet is
a. Diamagnetic materials
b. Paramagnetic materials
c. Ferromagnetic materials
d. Anti ferromagnetic materials

9)   Permanent magnet are manufactured by
a. Copper sulphate
b. Iron and cobalt
c. Cobalt and nickel
d. ALNICO

10)   The direction of magnetic materials when the current passes through the conductor is determined by
a. Right hand rule
b. Maxwell’s corkscrew rule
c. Left hand rule
d. Only (a) and (b)

11)   Coulomb’s First Law states that
a. Unlike poles attract each other
b. Like poles repel each other
c. Unlike poles attract each other and like poles repel each other
d. The force between two magnetic poles placed in a medium directly proportional to their pole strengths

 ANSWER: Unlike poles attract each other and like poles repel each other
12)   According to the couloumb’s second law, the force between two magnetic poles placed in a medium is
a. Directly proportional to their pole strengths.
b. Inversely proportional to the square of the distance between them
c. Inversely proportional to the absolute permeability of the surrounding medium
d. All of these

13)   The unit of magnetic flux is
a. Maxwell
b. Weber
c. Weber – m
d. Only (a) and (b)

14)   Reluctance in a magnetic material is a property by virtue of which it opposes the creation of
a. Electric flux
b. Magnetic flux
c. Electric field density
d. Electric lines of force

15)   The unit of magnetizing field intensity is
a. Newton / Weber
b. Ampere – turns / Weber
c. Newton – m / Weber
d. Only (a) and (b)

16)   One electron charge is equal to
a. 1.925 x 10–31C
b. 1.6019 x 10-19C
c. – 1.925 x 10–31C
d. – 1.6019 x 10–19C

17)   According to the coulomb’s law, the force between two point charges is
a. Directly proportional to the product of the charges
b. Inversely proportional to the square of the distance between them
c. Along the line joining them
d. All of these

18)   Electric field intensity is
a. Directly proportional to the force applied
b. Inversely proportional to the force applied
c. Directly proportional to the permittivity
d. Inversely proportional to the charge

 ANSWER: Directly proportional to the force applied
19)   The equation for electric flux density is given by

a. D = εV
b. D = εE
c. D = ε/E
d. D = ε/V

20)   Electric flux density is a function of
a. Charge
b. Position
c. Medium
d. Only (a) and (b)

21)   The most common waveforms of ac is
a. Square
b. Triangular
c. Sinusoidal
d. Saw tooth

22)   A radian is defined as the central angle, for which length of its arc
a. Should be greater than radius
b. Should be less than radius
c. Should be equal to the radius
d. None of these

23)   Peak to peak value of a sine wave is
a. Equal to the maximum or phase value of sine wave
b. Twice the maximum or phase value of sine wave
c. Half of the maximum or phase value of sine wave
d. Four times the maximum or phase value of sine wave

 ANSWER: Twice the maximum or phase value of sine wave
24)   The number of instantaneous values between zero and the peak value is
a. Zero
b. One
c. Eleven
d. Infinity

25)   If the
voltage increases from zero to peak value and decreases back to zero
during one alteration, then the average value must be

a. Less than zero
b. Greater than peak value
c. Between zero to peak value
d. None of these

 ANSWER: Between zero to peak value
26)   In Fleming’s right hand rule, the direction of the induced emf in the conductor is given by
a. Index figure
b. Middle figure
c. Thumb
d. None of these

27)   Yoke in a dc machine serves the function of
a. Providing mechanical support to the poles
b. Protects the dc machine from harmful atmospheric elements like dust, moisture and gases
c. Offers a path of low reluctances to the magnetic flux produced by the poles
d. All of these

28)   Laminations
or stampings are used to reduce the eddy current losses. The direction
of laminations should be such that

a. They are perpendicular to the paths of eddy current and flux both
b. They are parallel to the paths of eddy current and flux both
c. They are perpendicular to the paths of eddy current and parallel to the flux
d. They are parallel to the path of eddy current and perpendicular to the flux

 ANSWER: They are perpendicular to the paths of eddy current and parallel to the flux
29)   The terminal voltage in the separately excited generators is given by
a. V = Eg – Ia Ra
b. V = Eg + Ia Ra
c. V = Eg – Ia Ra – If Ra
d. V = Eg + Ia Ra – If Ra

 ANSWER: V = Eg – Ia Ra
30)   In a self excited generator, if the series field opposes the shunt field, then the generator is
a. Cumulatively compounded
b. Differentially compounded
c. Series generator
d. None of these

31)   Tangent galvanometer can be used to measure
a. Voltage
b. Current
c. Power
d. All of these

32)   Wattmeter is a / an
a. Indicating instrument
b. Integrating instrument
c. Recording instrument
d. All of these

33)   The magnetic effect is used in
a. Moving iron attraction type instrument
b. Moving iron repulsion type instrument
c. Electrostatic ammeters and voltmeters
d. All of these

34)   The springs should be
a. Free from mechanical stress
b. They should have a small resistance
c. Sufficient cross-sectional area
d. All of these

35)   In gravity control, at the zero position of the pointer the controlling torque is
a. Zero
b. One
c. 0.5
d. 7

36)   Alternating voltage can be generated by
a. By rotating a coil in a magnetic field
b. By rotating a magnetic field within a stationary coil
c. Either (a) or (b)
d. Neither (a) or (b)

37)   The amplitude or peak value or maximum value of an alternating voltage is given by the coefficient of the
a. Sine of the time angle
b. Cosine of the time angle
c. Tangent of the time angle
d. Cotangent of the time angle

 ANSWER: Sine of the time angle
38)   Root mean square value of current is equal to
a. 1.414 times the maximum value
b. 1.732 times the maximum value
c. Twice the maximum value
d. 0.707 times the maximum value

 ANSWER: 0.707 times the maximum value
39)   The ratio of maximum value to effective value of an alternating quantity is called
a. Crest factor
b. Peak factor
c. Amplitude factor
d. All of these

40)   The two alternating quantities could be added by constructing
a. Squares
b. Parallelograms
c. Rhombus
d. Trapeziums

41)   The undue deterioration in wiring due to the action of dampness, fumes, weather etc is
a. Appearance
b. Permanence
c. Mechanical immunity
d. Earthing

42)   For a two – way position control of lamp, the number of switches required is
a. One
b. Two
c. Three
d. Four

43)   The voltage of the earthed appliance when it is higher and when it is lower than the earth potential will
a. Fall to zero, fall to zero
b. Fall to zero, increase to zero
c. Increase to zero, increase to zero
d. Increase to zero, fall to zero

 ANSWER: Fall to zero, increase to zero
44)   Necessity of earthing is to
a. Protect the human being from shock
b. Maintain the line voltage
c. Protect tall building
d. All of these

45)   The most effective earth plate is
a. Copper plates
b. Cast – iron plates
c. Galvanized iron plates
d. All of these

46)   Three – phase induction motor is more suitable than single – phase because
a. It is self starting
b. Better efficiency compared to single – phase
c. Better power factor compared to single – phase
d. All of these

47)   Commutator motors have
a. Absolutely uniform torque
b. Approximately uniform torque
c. Non – uniform torque
d. None of these

48)   When
windings of 3 – phase induction motor is rotated in a magnetic field,
then the emf induced in each phase are of

a. Same magnitude but different frequency
b. Different magnitude but same frequency
c. Same magnitude and same frequency
d. Different magnitude and different frequency

 ANSWER: Same magnitude and same frequency
49)   In a 3 – phase star connected balanced induction motor, the line voltage is equal to the
a. 3 times the phase voltage
b. √3 times the phase voltage
c. 1/√3 times the phase voltage
d. 1/3 times the phase voltage

 ANSWER: √3 times the phase voltage
50)   In a star connected system, the current flowing through the line is
a. Greater than the phase current
b. Equal to the phase current
c. Lesser than the phase current
d. None of these

 ANSWER: Equal to the phase current

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