MCQs on Electronics Vacuum Tubes Question and Answers

MCQs on Electronics Vacuum Tubes Question and Answers

If you are searching MCQs on Electronics Vacuum Tubes likewise short questions and answers then you can find here all the relevant quizzes with answer key. If you are interested in the History of Basic Electronics through multiple choice questions with answer then read all the top 41 MCQs completely. You are eligible to qualify any Quiz / test / Interview after understanding all the questions and answers. If you are a students, technician and teacher then you can learn the basic concept of Vacuum Tubes construction, function and application.


Read More: MCQs on Integrated Circuits (ICs) Short Question and Answers Quiz


Vacuum Tube – Definition

Vacuum Tubes are such devices in which vacuum creates inside glass tube and the electrodes of Cathode Anode and Grid are used to control the flow of current for multiple functions. Now a days, Solid State Devices have taken the place of Vacuum tubes due to the more benefits and efficiency.

MCQs on Electronics Vacuum Tubes (Quiz Question and Answers)

Q1. When the free electrons leave the surface of a metal after applying external energy source is called______________.

  1. Electron Emission
  2. Electron Diffusion
  3. Forward Bias
  4. Reverse Bias

Answer: a

Q2. The electrons which are free to move when external energy is applied are called free electrons.
.   True/False

Answer: True

Q3. The another name of plate is ____________.

  1. Grid
  2. Cathode
  3. Anode
  4. Atom

Answer: c

Q4. When kinetic energy provides to the Metal Surface then the speed of electrons are increased.    True/False

Answer: True

Q5. The potential applied on the control grid of triode is called _____________.

  1. Signal
  2. Cathode Biasing
  3. Grid Biasing
  4. Plate Biasing

Answer: c 

Q6. When temperature increased from 2000°C then the electrons emission starts from the surface of Tungsten.     True/False

Answer: True

Q7. Electrons can easily move through the ____________.

  1. Vacuum
  2. Air
  3. Gass

Answer: a

Q8. A Force that resists the electrons emission from the surface of a metal is called Energy Barrier.     True/False

Answer: True

Q9. The emission of electrons from the surface of metal due to light is called ____________.

  1. Thermionic Emission
  2. Photo Electric Emission
  3. Field Emission
  4. Secondary Emission

Answer: b

Q10. The value of one electron volt is equal to 1.602×1019 Joule .     True/False

Answer: True

Q11. The unit of Work Function is _____________.

  1. Ampere Volt
  2. Volt Electron
  3. Energy Volt
  4. Electron Volt

Answer: d

Q12. The work function of a good emitter should be minimum.     True/False

Answer: True

Q13. A metal is heated inside Vacuum tube called_________________.

  1. Cathode
  2. anode
  3. Emitter
  4. a & c are correct

Answer: d

Q14. The quantity of electrons emitting from the surface of a metal depends on Temperature.     True/False

Answer: True

Q15. In the Photo Electric Emission, the kinetic energy of electrons depends on _________________.

  1. Frequency of Light
  2. Voltage
  3. Colour of Light
  4. Temperature

Answer: a

Q16. The electrons emission from the surface of a metal due to the high velocity electrons bombardment is called Secondary Emission.    True/False

Answer: True

Q17. The another name of field emission is_____________________.

  1. Thermal Emission
  2. Secondary Emission
  3. Photo Electric Emission
  4. Cold Cathode Emission

Answer: d

Q18. The secondary emission does not depend on temperature.     True/False

Answer: True

Q19. A Tube consists of three electrodes is called ___________.

  1. Diode
  2. Pentode
  3. Triode
  4. Tetrode

Answer: c

Q20. The tungsten materiel used as a Cathode in the large sizes of Vacuum tubes.   True/False

Answer: True

Q21. Diode is generally used for ___________.

  1. Detection
  2. Switching
  3. Rectification
  4. All are correct

Answer: d

Q22. DC supply used in Directly heated cathode.     True/False

Answer: True

Q23. When anode voltages are increased then space charge becomes ___________.

  1. Eliminate
  2. Decrease
  3. Increase
  4. Maintain

Answer: a

Q24. A Tube consists of two electrodes is called Diode.       True/False

Answer: True

Q25. The control grid of Triode is used to control the __________________.

  1. Flow of Electrons
  2. Flow of Holes
  3. Flow of Electrons & Holes
  4. All are correct

Answer: d

Q26. The another name of anode is Plate.    True/False

Answer: False

Q27. The relation between changing of Plate voltage and Grid voltage is called ___________.

  1. Amplification Factor
  2. Plate Resistance
  3. Mutual Conductance
  4. Saturation

Answer: a

Q28. When minimum negative voltages applied between Grid and Cathode then Anode current becomes cut-off..    True/False

Answer: True

Q29. The numbers of Grids in the Tetrode are _____________.

  1. 3
  2. 4
  3. 5
  4. 6

Answer: b

Q30. A huge change in the anode voltages due to the minimum changes in Grid voltage is called Amplification.     True/False

Answer: True

Q31. The extra grid in the Tetrode is called _____________.

  1. Suppressor Grid
  2. Screen Grid

Answer: b

Q32. A Pentode consists of 5 electrodes.     True/False

Answer: True

Q33. The relation between changing of Plate voltage and Plate current is called ___________.

  1. Amplification Factor
  2. Plate Resistance
  3. Mutual Conductance
  4. Saturation

Answer: b

Q34. A Pentode consists of 5 electrodes.     True/False

Answer: True

Q35. The number of Grids in the Pentode are__________________.

  1. 1
  2. 2
  3. 3
  4. 4

Answer: c

Q36. In the Pentode, Suppressor Grid is also available with Control Grid and Screen Grid.       True/False

Answer: True

Q37. The basic work of Suppressor Grid is to stop _____________ .

  1. Secondary Emission
  2. Flow of current
  3. Shielding Action

Answer: a

Q38. CRT stands for Cathode Ray Tube.       True/False

Answer: True

Q39. When increases the Plate voltages of Triode the Plate current becomes ____________.

  1. Increased
  2. Decreased
  3. Same
  4. stop

Answer: a

Q40. The coating of Phosphorus is available on the surface of CRT.       True/False

Answer: True

Q41. Deflection Plate Assembly of CRT consists of ____________ Plates.

  1. 1
  2. 2
  3. 3
  4. 4

Answer: d

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