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______________.
- Electron Emission
- Electron Diffusion
- Forward Bias
- 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 ____________.
- Grid
- Cathode
- Anode
- 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 _____________.
- Signal
- Cathode Biasing
- Grid Biasing
- 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 ____________.
- Vacuum
- Air
- 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 ____________.
- Thermionic Emission
- Photo Electric Emission
- Field Emission
- Secondary Emission
Answer: b
Q10. The value of one electron volt is equal to 1.602×10−19 Joule . True/False
Answer: True
Q11. The unit of Work Function is _____________.
- Ampere Volt
- Volt Electron
- Energy Volt
- 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_________________.
- Cathode
- anode
- Emitter
- 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 _________________.
- Frequency of Light
- Voltage
- Colour of Light
- 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_____________________.
- Thermal Emission
- Secondary Emission
- Photo Electric Emission
- 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 ___________.
- Diode
- Pentode
- Triode
- 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 ___________.
- Detection
- Switching
- Rectification
- 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 ___________.
- Eliminate
- Decrease
- Increase
- 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 __________________.
- Flow of Electrons
- Flow of Holes
- Flow of Electrons & Holes
- 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 ___________.
- Amplification Factor
- Plate Resistance
- Mutual Conductance
- 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 _____________.
- 3
- 4
- 5
- 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 _____________.
- Suppressor Grid
- 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 ___________.
- Amplification Factor
- Plate Resistance
- Mutual Conductance
- Saturation
Answer: b
Q34. A Pentode consists of 5 electrodes. True/False
Answer: True
Q35. The number of Grids in the Pentode are__________________.
- 1
- 2
- 3
- 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 _____________ .
- Secondary Emission
- Flow of current
- 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 ____________.
- Increased
- Decreased
- Same
- 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
- 2
- 3
- 4
Answer: d
