Discussion
The tunnel diode is useful in microwave oscillators and amplifiers because of the following reasons :
Answer: C
The tunnel diode is useful because it exhibits a negative resistance characteristic in the region between peak current IP and valley current IV.
A tunnel diode is very heavily doped, so its depletion layer is extremely thin and electrons can tunnel through the barrier. As forward voltage rises, current first rises to a peak and then falls to a valley as the bands move out of alignment. In that falling region, current decreases while voltage increases, a negative resistance, which can cancel the losses of a tuned circuit and sustain oscillation or provide gain at microwave frequencies.
The diode is heavily, not lightly, doped. A negative resistance supplies power to the circuit rather than absorbing it, and a positive resistance in that region would make it useless as an oscillator.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development