Electrical Engineering MCQ

Test your knowledge with important Electrical Engineering MCQ and their applications. These MCQs are beneficial for competitive exams too. Explore 30 + more Electrical Engineering MCQs at Bissoy

• The Q of a tuned amplifier is 50. If the resonant frequency for the amplifier is 1000kHZ, then bandwidth is ___________
  ক

  10kHz

  খ

  40 kHz

  গ

  30 kHz

  ঘ

  20 kHz
• The stabilisation of operating point in potential divider method is provided by ___________
  ক

  RE consideration

  খ

  RC consideration

  গ

  VCC consideration

  ঘ

  None of the above
• A class C amplifier always drives ___________ load
  ক

  A pure resistive

  খ

  A pure inductive

  গ

  A pure capacitive

  ঘ

  A resonant tank
• In a particular biasing circuit, the value of RE is about
  ক

  10 kΩ

  খ

  1 MO

  গ

  100 kΩ

  ঘ

  800 O
• Thermal runaway occurs when ___________
  ক

  Collector is reverse biased

  খ

  Transistor is not biased

  গ

  Emitter is forward biased

  ঘ

  Junction capacitance is high
• For proper operation of the transistor, its collector should have ___________
  ক

  Proper forward bias

  খ

  Proper reverse bias

  গ

  Very small size

  ঘ

  None of the above
• The zero signal IC is generally ___________ mA in the initial stages of a transistor amplifier
  ক

  4

  খ

  1

  গ

  3

  ঘ

  More than 10
• In parallel resonance, there is ___________
  ক

  Both voltage and current amplification

  খ

  Voltage amplifications

  গ

  Current amplification

  ঘ

  None of the above
• In series resonance, there is ___________
  ক

  Voltage amplification

  খ

  Current amplification

  গ

  Both voltage and current amplification

  ঘ

  None of the above
• In voltage divider bias, VCC = 25 V; R1 = 10 kΩ; R2 = 2.2 V ; RC = 3.6 V and RE =1 kΩ. What is the emitter voltage?
  ক

  7 V

  খ

  3 V

  গ

  5 V

  ঘ

  8 V
• The voltage gain of a tuned amplifier is ___________ at resonant frequency
  ক

  Minimum

  খ

  Maximum

  গ

  Half-way between maximum and minimum

  ঘ

  Zero
• The disadvantage of voltage divider bias is that it has ___________
  ক

  High stability factor

  খ

  Low base current

  গ

  Many resistors

  ঘ

  None of the above
• If biasing is not done in an amplifier circuit, it results in ___________
  ক

  Decrease in the base current

  খ

  Unfaithful amplification

  গ

  Excessive collector bias

  ঘ

  None of the above
• The size of a synchronous motor decreases with the increase in
  ক

  flux density

  খ

  horse power rating

  গ

  speed

  ঘ

  all of the above
• For power factor correction, synchronous motors operate at
  ক

  no-load and greatly over-excited fields

  খ

  no-load and under-excited fields

  গ

  normal load with minimum excitation

  ঘ

  normal load with zero excitation
• The rotor copper losses, in a synchronous motor, are met by
  ক

  d.c. source

  খ

  armature input

  গ

  motor input

  ঘ

  supply lines
• Riunting in a synchronous motor takes place
  ক

  When supply voltage fluctuates

  খ

  When load varies

  গ

  When power factor is unity

  ঘ

  Motor is under loaded
• An over excited synchronous motor is used for
  ক

  Fluctuating loads

  খ

  Variable speed loads

  গ

  Low torque loads

  ঘ

  Power factor corrections
• In case one phase of a three-phase synchronous motor is short-circuited the motor will
  ক

  Not start

  খ

  Run at $$\frac{2}{3}$$ of synchronous speed

  গ

  Run with excessive vibrations

  ঘ

  Take less than the rated load
• An important advantage of a synchronous motor over wound round induction motor is that
  ক

  its power factor may be varied at will

  খ

  its speed is independent of supply frequency

  গ

  its speed may be controlled more easily

  ঘ

  none of the above
• The power factor of a synchronous motor is better than that of induction motor because
  ক

  stator supply is relieved of responsibility of producing magnetic field

  খ

  mechanical load on the motor can be adjusted

  গ

  synchronous motor runs at synchronous speed

  ঘ

  synchronous motor has large air gap
• As the load is applied to a synchronous motor, the motor takes more armature current because
  ক

  The increased load has to take more current

  খ

  The rotor by shifting its phase backward causes motor to take more current

  গ

  The back e.m.f. decreases causing an increase in motor current

  ঘ

  The rotor strengthens the rotating field causing more motor current
• In a 3-phase synchronous motor, the negative phase sequence exists when the motor is
  ক

  supplied with unbalanced voltage

  খ

  under-loaded

  গ

  over-loaded

  ঘ

  none of the above
• The capacity of capacitor bank used in power factor correction is expressed in terms of
  ক

  kW

  খ

  kVA

  গ

  kVAR

  ঘ

  volts
• When 4 volts e.m.f. is applied across a 1 farad capacitor, it will store energy of
  ক

  2 joules

  খ

  4 joules

  গ

  6 joules

  ঘ

  8 joules
• Permittivity is expressed in
  ক

  Farad/sq-m

  খ

  Farad/meter

  গ

  Weber/meter

  ঘ

  Weber/sq-m
• Dielectric strength of a medium is usually expressed in
  ক

  J/mm

  খ

  C/m²

  গ

  kV/mm

  ঘ

  N/mm
• The value of E within the field due to a point charge can be found with the help of
  ক

  Faraday’s laws

  খ

  Kirchhoff's laws

  গ

  Coulomb’s laws

  ঘ

  none of the above
• The number of Faraday tubes of flux passing through a surface in an electric field is called
  ক

  electric flux

  খ

  electric flux density

  গ

  magnetic flux density

  ঘ

  electric charge density
• capacitors are used in transistor circuits.
  ক

  Ceramic

  খ

  Paper

  গ

  Air

  ঘ

  Electrolytic