Discussion
Home ‣ Electronics and Communication Engineering ‣ Microwave Communication See What Others Are Saying!
- Question
Assertion (A): PIN diode is used as a fast switch.
Reason (R): PIN diode has very high resistance when reverse biased and very low resistance when forward biased.
Options- A. Both A and R are correct and R is correct explanation of A
- B. Both A and R are correct but R is not correct explanation of A
- C. A is correct but R is wrong
- D. A is wrong but R is correct
- Correct Answer
- Both A and R are correct and R is correct explanation of A
ExplanationA PIN diode has an intrinsic (i) layer between p and n layers. When reverse bias is applied depletion layers are formed at p-i and i-n junctions.The effective/width of depletion layer increases by the width of i layer. It can be used as a voltage controlled attenuator.
At high frequencies the rectification effect ceases and impedance of diode is effectively that of i layer.
This impedance varies with the applied bias. It is used in high frequency switching circuits, limiters, modulators etc.
More questions
- 1. Which mode is called dominant mode in rectangular wave guide?
Options- A. TE01
- B. TE11
- C. TE10
- D. TE20 Discuss
Correct Answer: TE10
- 2. A 3 phase fully controlled converter is a
Options- A. 3 pulse converter
- B. 6 pulse converter
- C. 2 pulse converter
- D. 12 pulse converter Discuss
Correct Answer: 6 pulse converter
- 3. In a single phase half wave converter feeding resistive load and full wave converter (M - 2 connection) feeding a resistive load the circuit conditions are similar. The firing angle is a. Then the waveshapes of voltages across thyristors
Options- A. are similar
- B. are not similar
- C. may be similar or dissimilar
- D. are similar only for some values of a Discuss
Correct Answer: are similar
- 4. Some types of traps used in video IF amplifier of colour TV are
Options- A. shunt traps
- B. series traps
- C. absorption traps
- D. all of the above Discuss
Correct Answer: all of the above
Explanation:
All these are used.- 5. Which of the following devices exhibit negative resistance characteristics?
Options- A. UJT
- B. PUT
- C. Both UJT and PUT
- D. UJT, PUT and SBS Discuss
Correct Answer: Both UJT and PUT
- 6. In molecules of ionic crystals, orientation polarization is zero.
Options- A. True
- B. False Discuss
Correct Answer: True
- 7. Assertion (A): Magnetism can be explained by the theory of magnetic domains.
Reason (R): The existence of magnetic domains is evident from the Bitter powder patterns.
Options- A. Both A and R are true and R is correct explanation of A
- B. Both A and R are true but R is not correct explanation of A
- C. A is true but R is false
- D. A is false but R is true Discuss
Correct Answer: Both A and R are true but R is not correct explanation of A
- 8. Interference generated by electrical equipment and automobile ignition systems when observed closed to earth is
Options- A. horizontally polarized
- B. vertically polarized
- C. polarized both horizontally
- D. not polarized Discuss
Correct Answer: vertically polarized
- 9. Frequency range for satellite communication is
Options- A. 1 kHz to 100 kHz
- B. 100 kHz to 10 MHz
- C. 10 MHz to 100 MHz
- D. 1 GHz to 30 GHz Discuss
Correct Answer: 1 GHz to 30 GHz
- 10. To prevent a DC return between source and load, it is necessary to use
Options- A. resistor between source and load
- B. inductor between source and load
- C. capacitor between source and load
- D. either (a) or (b) Discuss
Correct Answer: capacitor between source and load
Explanation:
Capacitor offers infinite impedance to DC.
Comments
There are no comments.
More in Electronics and Communication Engineering:
Programming
Copyright ©CuriousTab. All rights reserved.