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131/2021 - Lineman - PWD (Electrical Wing)

You are currently taking the Lineman series. Good luck!

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Question 1
Which law states that in closed electric circuit the applied voltage is equal to the sum of the voltage drops?
A
Ohm”s law
B
Law of resistance
C
Kirchhoff”s first law
D
Kirchhoff”s second law
Question 2
What is the formula for Quantity of electricity (Q) ?
A
Current x Time
B
Voltage x Current
C
Current x Resistance
D
Voltage x Resistance
Question 3
Which one defines the change in resistance in Ohm (Ω) per degree centigrade (°C)?
A
Temperature effect
B
Laws of temperature
C
Temperature constant
D
Temperature coefficient
Question 4
Resistance of 250V, 100W lamp will be ________
A
0.4 Ω
B
25 Ω
C
625 Ω
D
2.5 Ω
Question 5
The resistivity of conductor ________
A
Decreases with increase of temperature
B
Increases very slowly by increasing the temperature
C
Increases sharply by increasing the temperature slightly
D
Increases very sharply in proportion to the temperature
Question 6
The reciprocal of resistance is ________
A
Conductance
B
Susceptance
C
Impedance
D
Reactance
Question 7
What are the three factors essential to make a simple electric circuit?
A
Switch, Voltage, Fuse
B
Current, Fuse, Conductor
C
Electromotive force, Current, Resistance
D
Potential difference, Quantity of electricity, Resistance
Question 8
If short circuit is occurred in an electric circuit, then the value of resistance will be ______
A
Low
B
High
C
Zero
D
Infinity
Question 9
The current in a series circuit is ________
A
Same throughout the circuit
B
Sum of individual resistor"s current
C
Depends Individual resistance value
D
Calculated by product of resistance and voltage
Question 10
The low value resistance can be measured by ________
A
Series ohm meter
B
Substitution method
C
Kelvin bridge method
D
Wheatstone bridge method
Question 11
As per Ohm"s law the current is ________
A
Directly proportional to the voltage
B
Inversely proportional to the voltage
C
Directly proportional to the resistance
D
Inversely proportional to the temperature
Question 12
Ohm"s law states the relation between ________
A
Current, E.M.F. and Voltage
B
E.M.F. Current and Resistance
C
Temperature, E.M.F. and Resistance
D
Voltage, Specific resistance and Resistance
Question 13
The formula to find the current (I) as per Ohm"s law is ________
A
I = R/V
B
I = V R^2
C
I = V / R
D
I = V R
Question 14
What is the change of resistance value of the conductor as its diameter is doubled?
A
Increases to two times
B
Decreases to four times
C
Decreases to half of the value
D
No change in value of the resistance
Question 15
What is the value of resistance in an open circuit ?
A
Zero
B
Low
C
High
D
Infinity
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Question 16
The parallel circuit is used for ________
A
House wiring
B
Continuity test
C
Decorative lighting
D
Ammeter connection
Question 17
Which is the application of series circuit?
A
Fuse in circuit
B
Voltmeter connection
C
Electrical lamp in houses
D
Shunt resistor in ammeter
Question 18
In Ohm"s law the condition is that
A
The temperature should vary
B
The temperature should remain constant
C
Current should be proportional to voltage
D
Ratio of V/I should be constant
Question 19
The resistance of a conductor on increasing the temperature
A
Decreases
B
Remains constant
C
Increases
D
Varies
Question 20
In a parallel circuit across each resistance
A
Current divides and voltage remains the same
B
Voltage divides and Current remains the same
C
Both divide
D
Both remains the same
Question 21
The property of a material which opposes the creation of magnetic flux in it is known as
A
Magnetomotive force
B
Reluctance
C
Permeance
D
Reluctivity
Question 22
Reciprocal of reluctance is
A
Susceptibility
B
Permeability
C
Permeance
D
Reluctivity
Question 23
Direction of forces on a conductor in a magnetic field is determined by ________
A
Fleming"s right hand rule
B
Fleming"s left hand rule
C
Right hand thumb rule
D
None of the above
Question 24
A property of material which opposes the creation of magnetic flux in it is known as ________
A
Magnetomotive force
B
Reluctance
C
Permeance
D
Reluctivity
Question 25
In electrical machines laminated cores are used with a view to reducing ________
A
Hysteresis loss
B
Eddy current loss
C
Copper loss
D
All of the above
Question 26
The magnitude of induced e.m.f. is directly proportional to the ________
A
Rate of change of current
B
Rate of change of flux linkage
C
Constant value of current
D
Constant value of flux linkage
Question 27
Static electromagnetic induction is adopted in ________
A
Generators
B
Alternators
C
Transformers
D
All of the above
Question 28
Eddy currents produced in a core ________
A
Increase useful energy
B
Create loss of useful energy
C
Strengthen the magnetic field
D
None of the above
Question 29
For an inductance current is proportional to ________
A
Magnetic field
B
Voltage across the inductance
C
Both magnetic field and voltage across the inductance
D
Neither magnetic field nor voltage across the inductance
Question 30
The electrical current is analogous to the magnetic circuit ________
A
Flux
B
Reluctance
C
Flux density
D
Permeability
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Question 31
Electric current is defined as ________
A
Flow of electrons in a conductor
B
Resistance offered in a circuit
C
Potential difference in a circuit
D
Electrons in atomic structure
Question 32
What is the polarity of an AC source?
A
Positive to ground
B
Negative to positive
C
Positive to negative
D
Change at regular intervals
Question 33
What is the standard domestic supply voltage in India as per Indian standard?
A
240 V
B
230 V
C
220 V
D
250 V
Question 34
Why AC transmission is preferred to long distance than DC?
A
Less line losses
B
It is easily available
C
Easy to carry high current
D
Current carrying capacity is more
Question 35
How much time is required by 50Hz AC supply to complete one cycle?
A
0.1 second
B
0.02 second
C
0.15 second
D
0.45 second
Question 36
What is the equation used to calculate the effective value (Vrms) of voltage in a wave?
A
Vrms = 0.707 Vmax
B
Vrms = 0.637 Vmax
C
Vrms = 1.114 Vmax
D
Vrms = 1.414 Vmax
Question 37
In an A.C. circuit, a low value of kVAR compared with kW indicates ________
A
Unity p.f.
B
High p.f.
C
Low efficiency
D
None of these
Question 38
In an A.C. circuit, the ratio of kW/kVA represents ________
A
Form factor
B
Power factor
C
Load factor
D
None of these
Question 39
In A.C. circuits, laminated iron is used to ________
A
Reduce eddy current loss
B
Reduce circuit permeability
C
Make assembly cheap
D
Increase heat radiation
Question 40
An alternating current or voltage is that which
A
Changes in direction only
B
Changes in magnitude only
C
Changes in both magnitude and direction
D
Has a random movement of electrons
Question 41
Compound generator is a
A
Separately excited generator
B
Self excited generator
C
Series generator
D
Shunt generator
Question 42
In DC lap winding number of parallel path A =
A
P
B
Z
C
60
D
N
Question 43
What is the emf in a 6 pole lap wound armature having 18 slots, 2 conductor per slot shaft rotating at 100 RPM, flux per pole is 0.1 Wb?
A
6V
B
36V
C
18V
D
60V
Question 44
As per Fleming"s right hand rule, middle finger points the direction of
A
Induced emf
B
Motion of conductor
C
Flux
D
None of the above
Question 45
Load current of a DC series generator is
A
equal to shunt field current
B
equal to series field current
C
sum of series and shunt field currents
D
sum of series field and armature currents
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Question 46
In a long shunt compound DC generator the shunt field winding is connected in parallel with
A
Series field
B
Armature
C
Parallel connected armature and series field combination
D
Series connected armature and series field combination
Question 47
The direction of rotation of DC motor can"t change by
A
Changing direction of Armature current
B
Changing direction of field current
C
Changing the direction of both armature and field currents
D
Changing the direction of supply voltage
Question 48
Speed of a DC motor
A
Directly proportional to flux
B
Directly proportional of back emf
C
Inversely proportional to supply voltage
D
Can"t change by increasing supply voltage
Question 49
Shaft torque in DC motor is
A
less than armature torque
B
greater than armature torque
C
equal to armature torque
D
square of armature torque
Question 50
A DC shunt motor is connected with 200V DC supply. It takes a line current of 18A. What will be the Armature current if shunt field resistance is 100 Ω?
A
36A
B
2A
C
20A
D
16A
Question 51
The motor used in mixer grinder
A
Stepper motor
B
Universal motor
C
Capacitor start motor
D
Compound motor
Question 52
An Induction motor with 6 poles rotating at a speed of 950 rpm using 50 Hz supply. The percentage of slip is
A
5%
B
3%
C
15%
D
0.5%
Question 53
D.O.L. starter is used to start the motor up to
A
25 HP
B
5 HP
C
7.5 HP
D
100 HP
Question 54
In slip ring induction motor starter 3 external variable resistances are
A
Connected in Series with stator circuit
B
Connected in Parallel with stator circuit
C
Connected in Star with rotor circuit
D
Connected in Delta with rotor circuit
Question 55
Which of the following is suitable for starting squirrel cage induction motor?
A
Rotor resistance starter
B
4 point starter
C
3 point starter
D
Auto transformer starter
Question 56
DIN rail is used to mount
A
Push button switches
B
Circuit breakers
C
Indicating lamps
D
Kit Kat fuses
Question 57
Which of the following is not a method of synchronisation?
A
Dark lamp method
B
Bright lamp method
C
Dark and bright lamp method
D
MMF method
Question 58
Centrifugal switch in a centrifugal pump motor is used to control
A
Supply through the starting winding
B
Supply through the running winding
C
Speed of the pump motor
D
Overload current
Question 59
Speed of a SCIM can be changed by
A
Varying number of poles
B
Varying supply phase sequence
C
Interchanging any two motor terminals
D
None of the above
Question 60
Growler is a
A
Armature testing machine
B
Earth testing machine
C
Coil winding machine
D
Polarity testing machine
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Question 61
Moderator is a part of
A
Tidal power plant
B
Solar power plant
C
Windmill
D
Nuclear power plant
Question 62
The part which reduces the water hammering effect in hydroelectric power plant system
A
Reservoir
B
Tail race
C
Surge tank
D
Pen stock
Question 63
Demand factor X connected load =
A
Average load
B
Power plant capacity
C
Maximum demand
D
Average demand
Question 64
Solar P.V. module efficiency will always be
A
greater than cell efficiency
B
less than cell efficiency
C
equal to cell efficiency
D
above 1
Question 65
Service lines are the part of
A
Primary transmission
B
Secondary transmission
C
Primary distribution
D
Secondary distribution
Question 66
Solar panel output does not depend on
A
Geographical location
B
Season of the year
C
Time of the day
D
AH capacity of connected battery
Question 67
Example for non-conventional energy source
A
Coal
B
Natural gas
C
Sun
D
Petroleum
Question 68
Conducting media in MHD Tunnel is
A
Hydrogen
B
Plasma
C
Solid conductor
D
Super conductor
Question 69
An 8 pole alternator produces 50 Hz supply. What will be the speed in rpm?
A
750
B
190
C
1500
D
1200
Question 70
Unit of solar irradiance is
A
m^2/W
B
W^2/m
C
W/m^2
D
m/W^2
Question 71
Advantage of D.C. Transmission system
A
No inductance
B
No phase displacement
C
Better voltage regulation
D
All of the above
Question 72
Skin effect of a conductor
A
Increases with increase in diameter
B
Inversely proportional to frequency
C
More in stranded condition
D
Less in solid condition
Question 73
Which is provided to prevent the entry of moisture in UG cables?
A
Bedding
B
Armouring
C
Metallic sheath
D
Serving
Question 74
Value of fusing factor is always
A
less than fusing current
B
less than one
C
more than fusing current
D
greater than one
Question 75
Which effect is accompanied by the production of ozone in OH line?
A
Skin effect
B
Corona effect
C
Proximity effect
D
Ferranti effect
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Question 76
Sag in overheadline S = wl2/8T , Here "l" stands for
A
Length of Pole
B
Length of conductor
C
Length of span
D
Length of cross arm
Question 77
Buchholz relay is located
A
In the main tank
B
In between conservator tank and main tank
C
In the breather
D
In between conservator and breather
Question 78
It gives support to the pole against falling
A
Lightning arrestor
B
Stay set
C
Cross arm
D
Earth wire
Question 79
Most of the substations are used to
A
Increase the power
B
Change the frequency
C
Change the voltage
D
Decrease the power
Question 80
Horn gap type surge diverter is a
A
Lightning arrester
B
Voltage regulator
C
Overload tripping contact
D
Air break circuit breaker
Question 81
The transistor configuration used for impedance matching is
A
CE
B
CB
C
CC
D
All of the above
Question 82
In PN junction diode the depletion region contains
A
Electrons
B
Holes
C
Immobile ions
D
None of the above
Question 83
Peak inverse voltage of centre tapped full wave rectifier is
A
Vm
B
2Vm
C
Vm/2
D
Vm/√2
Question 84
When transistor is used as a switch its region of operation is
A
Active region
B
Cut-off region
C
Saturation region
D
Both B and C
Question 85
The forbidden energy gap for silicon semiconductor is
A
1.21 eV
B
0.72 eV
C
0.3 eV
D
5 eV
Question 86
The rectification efficiency of a half wave rectifier is
A
81.2%
B
40.6%
C
0.48%
D
1.21%
Question 87
Unit of luminous flux is
A
lux
B
lumen
C
lumen-hours
D
lumen/m^2
Question 88
The material which can be used for filaments of incandescent lamps must possess
A
high melting point
B
low vapour pressure
C
high resistivity
D
All of the above
Question 89
According to inverse square law, the illumination of a surface is
A
directly proportional to distance between surface and the source
B
directly proportional to square of distance between surface and the source
C
inversely proportional to square of distance between surface and the source
D
inversely proportional to distance between surface and the source
Question 90
Electric motor used in mixer grinder is
A
universal motor
B
capacitor start induction motor
C
shaded pole motor
D
shunt motor
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Question 91
Which one of the following is an indicating type Instrument?
A
Voltmeter
B
Ammeter
C
Energy meter
D
Both (A) and (B)
Question 92
The instrument that totalizes events over a specific period of time is called
A
Recording instrument
B
Indicating instrument
C
Integrating instrument
D
None of the above
Question 93
Induction type measuring instruments are used for
A
AC measurements only
B
DC measurements only
C
Both AC and DC measurements
D
None of the above
Question 94
Calculate the deflection (Θ in degrees) for a moving coil instrument with deflection torque (Td) is given by 30 µNm and control spring constant is 2 µNm/degree.
A
100
B
150
C
200
D
600
Question 95
Which one of the following is a disadvantage of PMMC (permanent magnet moving coil instrument)?
A
PMMC can be modified into Ammeter and voltmeter.
B
PMMC exhibits no hysteresis.
C
Operation of PMMC is not significantly affected by stray magnetic field.
D
Errors due to ageing of control spring and the permanent magnet.
Question 96
Which of the following parameters remains unchanged between primary and secondary windings of a step up transformer?
A
Voltage
B
Current
C
Resistance
D
Frequency
Question 97
Which one the following is NOT a criterion for the parallel operation of transformer?
A
The transformers are to be connected properly so that the net voltage around the local loop is not zero.
B
Three phase transformers must have zero relative phase displacement on the secondary sides.
C
The transformers must have same voltage ratio to avoid no load circulatiing current.
D
There should exist only a limited disparity in the per unit impedances of the transformers.
Question 98
A 20 kVA, 50 Hz, 2000/200V distribution transformer has primary turns of 200. The maximum flux in the core is given by ________ webers.
A
0.09
B
0.045
C
0.0225
D
0.2
Question 99
Which of the following cooling methods is used for very large size transformers?
A
Natural cooling
B
Oil to air heat exchanger unit
C
Oil to water heat exchanger unit
D
None of the above
Question 100
The fusing characteristic is a curve between
A
Fusing time and voltage.
B
Fusing time and percentage of fuse current.
C
Fusing time and Temperature.
D
Fusing time and material type.