Electrical EngineeringI Smart Series MCQs COMPETITIVE EXAMS SET 5(401-500)

popular mcqs
  1. The probability that a loss of load occurs at or a given combination of system demand and generators availabilities is called

OR

  1. A loss of load occurs when system load exceeds the available generation capacity. The overall probability that there will be a shortage of power called
    A. Loss of load probability
    B. Load loss detachability
    C. Load probability
    D. None of above Ans. A
  2. The power in the circuit other than that which keeps on flowing from source to load and back is called
    A. Active power
    B. Reactive power
    C. Apparent power
    D. None of above Ans. A
  3. The current flowing through negative sequence Impedance is called
    A. Positive sequence current
    B. Zero sequence current
    C. Negative sequence current
    D. Neutral current Ans. C
  4. In a DC generator, eddy current is proportional to
    A. Thickness of lamination
    B. Square of thickness of laminations
    C. Inverse of square of thickness of laminations
    D. Inverse of Thickness or laminations Ans. B
  5. When an induction motor is connected to the supply, the rotation caused by
    A. Rotating magnetic field of stator
    B. Rotating magnetic field of rotor
    C. Electric field of stator
    D. Electric field of rotor Ans. A
  6. The fault shown in the figure is

A. Symmetric
B. Asymmetric
C. Lopified
D. Skewed Ans. A

  1. Ratio of magnetic flux density in material to the field in vacuum is called
    A. Absolute permeability
    B. Relative permeability
    C. Relative permittivity
    D. Absolute permittivity Ans. B
  2. plasma frequency of copper A. 2.6 X 1015
    B. 2.6 X 106
    C. 2.6 X 1012
    D. 2.6 x 103
    Ans. A
  3. When a current carrying conductor is placed in a magnetic field it is subjected to Electromagnetic or Lorentz force which is
    A. Parallel to field
    B. Perpendicular to field
    C. 45 degrees to field
    D. 135 degrees to field Ans. B
  4. In an infinite sheet charge is uniformly distributed in YZ plane, the direction of electric field will be
    A. Along x-axis
    B. Along z-axis

C. Along y-axis
D. can be along any of these Ans. A

  1. Dq/ Dt is called ꞏ
    A. Current
    B. Charge
    C. Capacitance
    D. Voltage Ans A
  2. Four inductors 10mH, 20mH , 25mH , and 5mH are connected in series net inductance will be .
    A. 10mH
    B. 25mH
    C. 60mH
    D. 75mH Ans. C
  3. Four inductors 10mH, 10.5mH, 20 mH and 20.5mH are connected in parallel, the equivalent inductance will be
    A. 4.3mH
    B. 3.4mH
    C. 6mH
    D. 7mH Ans. B
  4. In series RLC circuit R=2 ohm, L=l H, C=l F, the system response would be
    A. Damped
    B. Underdamped
    C. Critically damped
    D. Overdamped Ans. C
  5. For undamped system, R=l ohm, L=2 H, C=2 F, the value of frequency
    A. 0.l
    B. 0.5
    C. 1.0
    D. 1.5
    E. 2.0
    Ans. B
  6. Electrical field with uniform charge density on sphere
    A. X>R
    B. X<R
    C. X=R
    D. None Ans. B
  7. Addition of small displacements along a zig-zag path and summing is
    A. Equal to vector pointing from initial to final point
    B. Work done
    C. Impossible to find
    D. Not equal to single vector Ans. A
  8. In Kirchhoff’s law summation of all the currents entering or leaving a node are
    A. Unity
    B. Zero
    C. Infinity
    D. None of these Ans. B
  9. In an RLC series circuit the total Impedance between two end point would be A. Z=ƒ𝑅^2 + {𝑋𝐿 — 𝑋C)^2
    Ans. A
  10. In cathode Ray Oscilloscope vertical axis represent and horizontal axis represents
    B. Volts/Division; Time/Division
    C. Time/Division; Volts/Division I
    D. Voltage, Resistance
    E. Resistance, Current Ans. A
  11. Instrument for measuring ocular focus or refraction of eyes
    A. Drum meter
    B. Ellipsographs
    C. Durometer
    D. Dioptometer
    E. Electroretinography Ans. D
  12. For input function of 2 Boolean variables there are Boolean algebra functions.
    A. 12
    B. 8
    C. 16
    D. 4 Ans C
  13. Diode clampers are used to shift AC voltage waveform up or down in positive and negative peak by inserting
    A. DC level
    B. AC level
    C. Both AC and DC level
    D. None of above Ans. A
  14. Rectifiers employ operational amplifier to eliminate diode voltage
    A. Passive circuit
    B. Active circuit

C. Saturation circuit
D. Non-saturation circuit Ans. A

  1. Which of the following statements is incorrect?
    A. Switching regulators use switching speeds of 20 kHz or more
    B. great advantage of switching regulators is that their power consumption is very low
    C. Both bipolar transistors and FETs have very good switching characteristics
    D. The output voltage of a switching regulator is controlled by altering the switching frequency
    Ans. D
  2. SCR is turned on by applying gate pulse, now it can be turned off when
    A. Anode current falls below holding current
    B. Anode current falls below latching current
    C. Anode current Increase above the holding current
    D. None of the above Ans. A
  3. Which of the following Is normal operation of NPN TRANSISTOR?
    A. Emitter to base junction Is forward biased and collector to base junction reverse biased
    B. Emitter to base junction is forward biased and collector to base junction forward biased
    C. Emitter to base junction is reverse biased and collector to base junction reverse biased
    D. Emitter to base Junction is reverse biased and, collector to base junction forward biased
    Ans. A
  4. If first byte of the data is stored at address, 8086 can read the entire word in one operation.
    A. Odd address
    B. Even address
    C. 0521H
    D. Any segment Ans. B
  5. Instead of establishing different connections of wires, modern device are built with virtual relay contacts, these are programmed using
    A. Assembly language
    B. Machine language
    C. Ladder logic
    D. Visual basic Ans. C
  6. First generation of computers use
    A. Microprocessors
    B. IC’s
    C. vacuum tubes
    D. None of the above

Ans. C

  1. Program counter is used to
    A. Store address of the next instruction to be executed
    B. Store address of the previous instructions
    C. Store address of the segment
    D. None of these Ans. A
  2. Intel MCS51 is commonly known as ꞏ
    A. 8080
    B. 8051
    C. 5151
    D. None of the above Ans. B
  3. Data storage system is provided by
    A. Control mechanism
    B. Register
    C. Logic gates
    D. Both A & B Ans. C
  4. Inverse of even function
    A. Even
    B. Odd
    C. Linear
    D. Does not exist Ans. D
  5. For multiple video channels, digital modulation and diodes are necessary.
    A. Zener
    B. Schottky
    C. Laser
    D. Light emitting Ans. C
  6. Proper way to apply time shifting and scaling on a signal is
    A. Time shifting Is applied first and then scaling
    B. Scaling is applied first and then time shifting
    C. Anyone can be applied irrespective of order
    D. Only one operation can be performed Ans. A
  7. In closed loop control system feedback strategy is
    A. Input dependent
    B. Fail safe
    C. Error driven
    D. Both A & B Ans. C
  8. Asymptotic stability of a control system is determined by
    A. Eigen values
    B. Poles and zeros
    C. Only zeros
    D. None of above Ans. A
  9. Baseband analog Intensity modulation Is done by modulating applied to LED
    A. Voltage
    B. Curent
    C. Frequency
    D. Amplitude Ans. B
  10. Two coherent modes in optical fiber detection are homodyne and
    A. Heterodyne
    B. Balanced detection Ans. A
  11. identify correct statement about FM and AM
    A. More power is required for FM than AM
    B. Less power ls required for FM than AM
    C. Equal power Is required for FM and AM
    D. None of the above Ans. B
  12. The autocorrelation of discrete Pseudo noise sequence is similar to
    A. Random atmospheric generator
    B. White noise
    C. Ground clutches
    D. Audio distortion Ans. B
  13. Bandwidth should be to avoid distortion of the signal
    A. Equal
    B. Twice
    C. Thrice 4 times Ans. B
  14. To avoid aliasing of the signal, signal frequency should be
    A. Equal
    B. Twice ꞏ
    C. Thrice
    D. Half Ans. C
  15. y’+2y = 4 (X + y )2 is order equation
    A. First
    B. Second Ans. A
  16. π Method is used
    A. line to neutral capacitance is divided by two halves
    B. Capacitance C and reactance are equally localized at midpoint and sending, receiving end
    Ans. A
  17. In a power plant, coal is carried from storage place to boilers generally by means of
    A. Bucket
    B. V belts
    C. Trolleys
    D. Manually Ans. B
  18. A condenser in a thermal power plant condenses steam coming out of
    A. Boiler
    B. Super heater
    C. Economizer
    D. Turbine Ans. D
  19. Which variety of coal has lowest calorific value?
    A. Steam coal
    B. Bituminous coal
    C. lignite
    D. Anthracite Ans. C
  20. In position control systems, the device used for providing rated feedback voltage is called
    A. Potentiometer
    B. Synchro transmitter
    C. Synchro transformer
    D. Tachogenerator Ans. D
  21. Phase margin of system specifies
    A. Absolute stability
    B. Frequency response
    C. Relative stability
    D. instability Ans. C
  22. In force voltage analogy the moment of inertia is analogous to
    A. Capacitance
    B. Inductance
    C. Inverse capacitance
    D. Inverse inductance
    ꞏAns. B
  23. Which of the following non linearity is caused by servo motor?
    A. Coulomb friction
    B. Dead space
    C. Saturation
    D. Dissemination Ans. C
  24. The transfer function of a system is used for the calculation of
    A. Output for a given input
    B. Steady state gain
    C. Order of the system
    D. Time constant Ans. A
  25. A balanced modulator produces
    A. AM
    B. SSBꞏ
    C. VSB
    D. DSB Ans. D
  26. In common base amplifier circuit, the output is taken from
    A. Collector
    B. Emitter
    C. Base
    D. Both A & C Ans A
  27. The greatest possible amplification is obtained in Common emitter circuit
    A.Common base B.circuit Common C.coilect6r circuit D.None
    Ans. A
  28. An Inductor is operated at 50 Vac with a frequency of 10 KHz and current of 7.96 mA then the value of L is
    A. 100mH
    B. 10mH
    C. 1mH
    D. 1H Ans A
  29. Which type of copper wire will have the highest tensile strength?
    A. Soft drawn
    B. Medium drawn
    C. Hard drawn
    D. None Ans. C
  30. At breakaway point, several branches of root loci coalesce because system characteristics equation has
    A. Single root
    B. All roots on right hand side of S plane
    C. Several roots
    D. Imaginary roots only Ans. C
  31. Excessive noise in a control system may result in
    A. Reduction in gain
    B. Reduction in bandwidth
    C. Oscillation
    D. Saturation in amplifying stages Ans. D
  32. If 3000 kW power is to be transmitted over a distance of 30 km what will be the voltage level to transmit the power?
    A. 11kV
    B. 33 kV
    C. 66 kV
    D. 132 kV Ans. B
  33. Basically, a controller is a
    A. Amplifier
    B. Clipper
    C. Comparator
    D. Summer Ans. C
  34. In a 3-phase half wave diode rectifier, the ratio of average output voltage to per phase maximum AC voltage is
    A. 0.827
    B. 1.57
    C. 3.2
    D. 0.25
    Ans. A
  35. AGC voltage is applied to the stages which are
    A. Before the detector stage
    B. After the detector stage
    C. Detector stage
    D. Both A & C Ans. D
  36. Receiver having poorer IF selectivity will have poor
    A. Sensitivity
    B. Blocking of adjacent channels
    C. Diverse reception

D. None Ans. B

  1. Padders are provided in a radio receiver
    A. To improve sensitivity
    B. Improve tracking
    C. For reducing noise of
    D. For fine tunning Ans. B
  2. Fidelity in a communication receiver is provided by
    A. Audio stage
    B. Detector stage
    C. Mixer stage
    D. All of above Ans D
    ***If ‘all of the above’ is not given then tick audio stage
  3. Which of the following communication system is digital?
    A. FM
    B. AM
    C. PAM
    D. PCM Ans. D
  4. A PWM signal can be generated by
    A. A monostable multivibrator
    B. Unstable multivibrator
    C. Integrating the PPM signal
    D. Differentiating the PPM signal Ans. D
  5. Optical fibers rely for their operation on the phenomenon of
    A. Reflection
    B. Refraction
    C. Dispersion
    D. Total internal reflection Ans. D
  6. In order to get the original signal from the sampled signal, which of the following filters should be necessarily used
    A. Band stop signal
    B. Low pass filter
    C. High pass filter
    D. Band pass filter Ans. B
  7. In an AC circuit which of the following elements consume power
    A. Inductor

B. Capacitor
C. Resistor
D. All Ans. C

  1. Which of the following is a closed loop system?
    A. Electric switches
    B. Car starter
    C. Auto pilot of an aircraft Ans. C
  2. Which of the following losses of dc motor decrease with the increase in load?
    A. Friction & windage loss
    B. Brush contact loss.
    C. Core loss
    D. None of above Ans. D
  3. For Zener regulation we don’t want Zener current to fall below knee current because
    A. It will damage the physical structure of Zener diode
    B. A lot amount of heat Will be Produced
    C. It will consume more electrical Power Ans. A
  4. A wire mesh or electrode between the cathode and anode is known as
    A. A Plate
    B. Grid
    C. Filament
    D. None Ans. B
  5. Collection of structured data which may be manipulated at some or all of the data held is called
    A. Information
    B. Database
    C. Controlling
    D. Security Ans. B
  6. The control unit directs the ALU to perform an arithmetic operation, the machine cycles is involved in its
    A. First step
    B. Third step
    C. Second step
    D. Fifth step Ans. B
  7. In Poisson distribution, the probability of success is
    A. 1

B. 0.5
C. 0.2
D. 0 Ans. D

  1. In a light bulb factory, it is found that the probability of bulb being defective is 0.12. Estimate how many defective bulbs will be produced in total of 8000 bulbs
    A. 260
    B. 960
    C. 9600
    D. 96000
    Ans. B
  2. Technique which Is used to enable multiple broadbands transmitted over single mode fiber
    A. Subscriber multiplexing
    B. Wavelength division multiplexing
    C. Time division multiplexing
    D. Frequency division multiplexing Ans. A
  3. cells make concentration layer of the lens.
    A. Strong
    B. Fibrous
    C. Weak
    D. Optical Ans. B
  4. Most data communications involving telegraph lines use
    A. Simplex lines
    B. Wideband lines
    C. Narrowband lines
    D. Dialed service Ans. C
  5. In a critically damped system, the damping factor is
    A. Zero
    B. Less than unity
    C. Greater than unity
    D. Unity Ans. D
  6. If two vectors a and b are anti-parallel to each other, then the resultant vector is
    A. 2b
    B. a + b
    C. a – b
    D. 2a Ans. C
  7. The scalar product of two parallel vectors is equal to the
    A. The product of their magnitude

B. Equal to their magnitude
C. The product of their directions
D. All of the above Ans. A

  1. A thyristor has alternating semiconductor layers and Junctions are present.
    A. Three, four
    B. Four, three
    C. Three, two
    D. None Ans. B
  2. A programmer would most likely prepare a flow chart for a
    A. Specific program flow
    B. General program flow chart
    C. Specific system design
    D. General system design Ans. A
  3. In digital electronics, numbers of basic operations or functions are
    A. 5
    B. 1
    C. 2
    D. 4 Ans. C
  4. 127 may be represented in binary number system as 0001 1111B
    A.1000 0000B
    B.111 1111
    C.11111111
    Ans C
  5. Which gate is called universal gate?
    A. AND
    B. NOT
    C. NOR
    D. XNOR
    E. OR Ans. C
  6. The phenomenon in which changing current in one coil induces emf In another coil placed near to the first is called
    A. Mutual induction
    B. Self-induction
    C. Primary induction
    D. Secondary induction Ans. A
  7. Transformer oil must be free from

A. Odour
B. Gases
C. Sulphur
D. Moisture Ans. D

  1. A current transformer should not have

A. A movable secondary winding
B. A high resistance across secondary
C. Primary and secondary open circuited
D. None of above Ans. B

  1. In a piston the maximum temperature occurs at
    A. Ring section
    B. Top sides
    C. Top center Ans C
  2. Which of the following enters the super heater of a boiler?
    A. Cold steam
    B. Hot water
    C. Wet steam
    D. superheated steam Ahs. C
  3. In outdoor substation the lightning arresters are placed. nearer to
    A. Isolator
    B. Current transformer
    C. Power transformer
    D. Circuit breaker Ans. C
  4. Which of the following type tests are conducted on isolator?
    A. Temperature rise test
    B. Impulse voltage withstand test
    C. Short time current test
    D. All Ans. D

Electrical EngineeringI Smart Series MCQs COMPETITIVE EXAMS SET 6(501-600)

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