Steel Authority Of India Limited SAIL Model Questions Electrical Engineering Questions

Steel Authority Of India Limited
SAIL Model Questions
Electrical Engineering Questions

Q. In a D.generator, if the brushes are given a small amount of forward shift, the effect of
armature is

• Totally demagnetizing
• Totally magnetizing
• Partly demagnetizing and partly cross magnetizing
• Totally cross magnetizing

Q. The air gap between stator and armature of an electric motor is kept as small as possible

• To get a stronger magnetic field
• to improve the air circulation
• To reach the higher speed of rotation
• To make the rotation easier.

Q. Two series motors are coupled.One motor runs as generator and other as motor. The friction losses of the two machines will be equal when

• Both operates at same voltage
• Both have same back emf
• Both have same speed
• both have same excitation

Q. Plugging of D.motor is normally executed by

• Reversing the field polarity
• Reversing the armature polarity
• Reversing both the armature and field polarity
• Connecting a resistance across the armature.

Q. Transformer oil transformer provides

• Insulation and cooling
• Cooling and lubrication
• Lubrication and insulation
• Insulation, cooling and lubrication

Q. Leakage fluxes of transformer may be minimized by

• Reducing the magnetizing current to the minimum
• Reducing the reluctance of the iron core to the minimum
• Reducing the number of primary and secondary turn to the minimum
• Sectionalizing and interleaving the primary and secondary windings

Q. Electric power is transformed upon one coil to other coil in a transformer

• Electrically
• Electro Magnetically
• Magnetically
• Physically

Q. The most suitable and economical connection for small high voltage transformer is a

• Star- Delta connection
• Delta- Delta connection
• Delta- Star connection
• Star- Star connection

Q. An alternator is said to be over excited when it is operating at

• Unity power factor
• Leading power factor
• Lagging power factor
• Either lagging or leading power factor

Q. In an A.machine, the armature winding is kept stationary while the field winding is kept
rotating for the following reason

• Armature handles very large currents and high voltages
• Armature friction involving deep slots to accommodate large coils is easy if armature is kept stationary
• Ease of cooling the stator than rotor
• None of the above.

Q. In a synchronous motor, the torque angle is the

• Angle between the rotating stator flux and rotor poles
• Angle between the magnetizing current and back emf
• Angle between the supply voltage and back emf
• None of the above

Q. A 3-phase synchronous motor is said to be "floating" when it operates

• On no load and without loss
• On constantly varying load
• On pulsating load
• On high load and variable supply voltage

Q. Speed of synchronous motor depends upon

• Number of poles
• Supply frequency
• Both (a) and (b) 
• Neither (a) nor (b)

Q. Imbalance in the shaft of an induction motor occurs due to

• Slip rings
• Overheating of winding
• Non uniform of air gap
• Rigid construction

Q. Squirrel cage induction motor has

• Zero starting torque
• Very small starting torque
• Medium starting torque
• Very high starting torque

Q. The principle of operation of a 3-phase induction motor is similar to that of a

• Synchronous motor
• Repulsion - start induction motor
• Transformer with a shorted secondary
• Capacitor - start, induction - run motor

Q. The speed/load characteristics of a universal motor are similar to those

• D.shunt motor
• D.series motor
• A.motor
• None of the above

Q. Single phase A.motor generally used for vacuum cleaners is

• Universal motor
• Repulsion motor
• Hysteresis motor
• Reluctance motor

Q. Buchholz relay is used for the protection of

• Switch yard
• Transformers
• Alternators
• Transmission lines

Q. The type of braking used in traction system is

• Mechanical braking
• Electro - pneumatic braking
• Vacuum braking system
• All the above

Q. The function of processing zenger diode in a UJT circuit used for triggering of SCRs is to

• Expedite the generation of triggering pulses
• Delay the generation of triggering pulses
• Provide a constant voltage to UJT to prevent erratic firing
• Provide a variable voltage to UJT as the source voltage changes

Q. The frequency of a ripple in the output voltage of a 3 - phase semi converter depends upon

• Firing angle and load resistance
• Firing angle and supply frequency
• Firing angle and load inductance
• Only on load circuit parameters

Q. The SCR is turned off when the anode currents falls below

• Forward current rating
• Break - over voltage
• Holding current
• Latching

Q. V4 characteristics of emitter of a UJT is

• Similar to CE with linear and saturation region
• Similar to FET with a linear and pinch of region
• Similar to tunnel diode in some respects
• Linear between the peak point and valley point

Q. A transformer works on

• DC
• AC
• AC & DC both
• Neither AC not DC

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SAIL ELECTRICAL ENGINEERING PREVIOUS YEAR PAPERS I

STEEL AUTHORITY OF INDIA LIMITED

SAIL Management Trainee

Electrical Engineering Model Paper

Q.1.Two 100-W, 200-V lamps are connected in series across a 200-V supply. The total power consumed by each lamp will be _____ watts.

• 200
• 100
• 50
• 25 

Q.2.The material used for fuse must have

• low melting point and low specific resistance
• high melting point and low specific resistance
• low melting point and high specific resistance
• none of these

Q.3.The purpose of introducing reactor in the ignition circuit of mercury are rectifier is to limit the

• voltage of the circuit
• rate of change of flux in the circuit
• current in the circuit
• rate of change of current in the circuit

Q.4.Sparking occurs when a load is switched off because the circuit has high

• a resistance
• inductance
• capacitance
• none of these

Q.5.The usual value of the surge impedance of a telephone line is ______ohm.

• 75
• 600
• 500
• 250

Q.6.In the case of a lossy capacitor, series equivalent resistance value will be

• small
• large
• very small
• none of these

Q.7.Time constant of an R-C circuit increases if the value of resistance is

• decreased
• increased
• neither (a) nor (b)
• either (a) or (b)

Q.8.Sparking between contacts can be reduced by inserting a

• capacitor in parallel with contacts
• resistance in the line
• capacitor in series with contacts
• none of these

Q.9.dBm is a

• ratio of power
• unit of power
• unit of voltage
• none of these

Q.10.Decibel is a unit of

• frequency
• impedance
• power ratio
• none of these

Q.11.The absolute unit of resistance is of the dimension of

• velocity
• length
• acceleration
• none of these

Q.12.The absolute unit of inductance is of the dimension of

• time
• length
• mass
• none of these

Q.13.The applied voltage from the circuit being checked is disconnected when an ohmmeter is used because

• the current will decrease the resistance
• the ohmmeter has its own battery
• no current is needed for meter movements
• none of these

Q.14.An accurate voltmeter must have an internal impedance of

• very high value
• very low value
• low value
• none of these

Q.15.A moving –coil instrument can be used to measure

• high frequency a.c.
• low frequency a.c
• both d.c. and a.c
• direct current

Q.16.The voltage drop across the moving coil of a 50-µ A (f.s) PMMC meter at full- scale deflection is ---- the voltage drop across that of a 1-mA (fs) PMMC meter at full-scale deflection.

• less than
• approximately equal to
• greater than
• none of these

Q.17.Voltage stress is maximum in a cable at the surface of the

• insulator
• sheath
• conductor
• none of these

Q.18.The coefficient of coupling between two air core coils depends on

• mutual inductance and self inductances of the two coils
• mutual inductance between two coils only
• self inductances of the two coils only
• none of these

Q.19.The location of lightning arrestor is

• away from the transformer
• near the transformer
• near the circuit breaker
• none of these

Q.20.A conductor of length 1 meter moves at rt. angles to a magnetic field of flux density 1 Wb/m2 with a velocity of 25 m/s. The induced e.m.f. in the conductor will be ----- volt.

• 75
• 25
• 50
• 100

Q.21.In electrical machines, laminated cores are used with a view to reducing

• eddy current loss
•  
• hysteresis loss
•  

Q.22.A battery

• always delivers power
• always absorbs power
• absorbs power when the internal resistance is non-zero but delivers power when the internal resistance is zero
• can absorb or deliver power depending upon the circuit to which it is connected

Q.23.Decibel is a

• unit of voltage
• unit of power
• ratio of power
• none of these

Q.24.Deflection of pointer of a permanent-magnet moving-coil meter for fixed current is _______ flux density in the airgap between magnetic pole shoes and coil.

• independent of
• directly proportional to
• inversely proportional to
• none of these

Q.25.A moving-iron meter is useful for voltage measurement at _______frequencies.

• high
• low
• very high
• none of these

Q.26.A thermocouple instruments would be used to measure alternating current only?

• low
• very low
• high
• none of these

Q.27.Which of the following instruments will be used to measure alternating current only?

• moving – iron (attraction-types) ammeter
• moving – iron voltmeter
• permanent-magnet type ammeter
• induction-type ammeter

Q.28.A milliammeter can be used

• only as an ammeter
• as a voltmeter
• both as voltmeter and ammeter
• none of these

Q.29.To measure the e.m.f. of a Weston standard cell, one would use a/an 

• electrostatic voltmeter
• hot-wire voltmeter
• galvanometer
• potentiometer–Answer

Q.30.Deflection sensitivity of deflecting plates of cathode ray tube ____ the distance between deflection pates.

• is inversely proportional to
• is directly proportional to
• does not depend on
• none of these

Q.31.Deflection sensitivity of deflecting plates of a cathode ray tube ___the accelerating anode (A3) voltage.

• is inversely proportional to
• is directly proportional to
• does not depend on
• none of these

Q.32.A moving – coil instrument can be used to measure

• direct current
• alternating current
• both direct current and alternating current
• none of these

Q.33.The frequency stability of a crystal oscillator depends upon

• tuned circuit
• crystal
• crystal as well as the tuned circuit
• none of these

Q.34.Hay bridge is usually used for measuring

• resistance
• capacitance
• inductance
• none of these

Q.35.Schering bridge is used for measuring

• capacitance
• inductance
• frequency
• none of these

Q.36.The Wien’s bridge is particularly useful for measuring frequencies of _______value.

• low
• very high
• high
• very low

Q.37.Impedance relay is used to protect

• line within a particular zone
• line beyond a particular zone
• the whole transmission system
• none of these

Q.38.Buchholz relay is used in ______ protection.

• line
• generator
• transformer
• none of these

Q.39.Kirchhoff’s voltage law is not valid for a non-linear network.

• True
• False

Q.40.If a piece of metal wire is stretched, its resistance will increase.

• True
• False

Q.41.In mesh analysis of a network, all the mesh currents must necessarily be either clock-wise or anticlock-wise.

• True
• False

Q.42.An uncharged capacitor is connected across a charged one.There will flow an impulsive current through the circuit.

• True
• False

Q.43.If R, L and C denote resistance, inductance and capacitance respectively, the quantity RC has the same dimensions as that of R/L.

• True
• False

Q.44.If R, L and C denote resistance, inductance and capacitance respectively, then the quantity CR2 has the dimensions, of L.

• True
• False

Q.45.A battery will not cause any current to flow, when it is connected across a pure capacitor, in the steady state even if the capacitor value varies with time.

• True
• False

Q.46.When two capacitors C1 and C2 are connected in series, the effective capacitance is C1+C2

• True
• False

Q.47.The flux linked with a coil of inductance l carrying a current i is ddt(Li).

• True
• False

Q.48.When one wants to connect two batteries in parallel to draw larger current than what can be supplied by one battery, it suffices to ensure that their e.m.f.s. are equal.

• True
• False

Q.49.An ideal battery can supply infinite current

• True
• False

Q.50.1 GHz means 100 Hz.

• True
• False

META TAGS:-SAIL PREVIOUS YEAR PAPERS I PSU ELECTRICAL EXAM PAPERS I PSU ELECTRICAL STUDY MATERIALS I PSU ELECTRICAL ENGINEERING STUDY MATERIALS I DOWNLOAD ELECTRICAL ENGINEERING SOLVED PAPERS I SAIL ELECTRICAL ENGINEERING SAMPLE PAPERS I ELECTRICAL ENGINEERING SAMPLE PAPERS I DOWNLOAD ELECTRICAL SOLVED PAPERS I ELECTRICAL SOLVED PAPERS I SAIL MANAGEMENT TRAINEE LAST 10 YEAR PAPERS I IES ELECTRICAL STUDY MATERIALS I

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SAIL ELECTRICAL ENGINEERING SOLVED PAPERS I

STEEL AUTHORITY OF INDIA LIMITED

SAIL Management Trainee

Electrical Engineering Model Papers

• SAIL MT Electrical Engineering Model Papers-1

• SAIL MT Electrical Engineering Model Papers-2

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• SAIL MT Electrical Engineering Model Papers-5

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• SAIL MT Electrical Engineering Model Papers-17

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• SAIL MT Electrical Engineering Model Papers-19

• SAIL MT Electrical Engineering Model Papers-20

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