NEET Physics is the very imporatant paper in the Medical Entrance EXAM. So these NEET Physics MCQs and Answers for all Concepts as per the new syllabus. Practice daily with these NEET Physics objective questions on air pollution . NEET Physics Photodiode Multiple Choice Questions
MCQs on Photodiode :
1. Photodiode is used in the detection of
(A) Visible light
(B) Invisible light
(C) No light
(D) Both visible and invisible light
Answer
Answer: (D) Both visible and invisible light
2. In using a photodiode as a photodetector, it is invariably reverse biased
(A) The power consumption is much reduced compared to reverse biased condition
(B) Only when the photodiode is reverse biased the incident photons produce electron-hole pairs
(C) Only if the diode is reverse biased light variations can be converted into current variations
(D) When photons are incident on the diode, the fractional change in the reverse current is much greater than the fractional change in the forward current
Answer
Answer: (D) When photons are incident on the diode, the fractional change in the reverse current is much greater than the fractional change in the forward current.
3. The maximum wavelength of photons that can be detected by a photodiode made by a semiconductor of bandgap 2eV is about
(A) 620 nm
(B) 700 nm
(C) 740 nm
(D) 1240 nm
Answer
Answer: (A) 620 nm
4. The presence of dark current decreases the sensitivity of the photodiode to light
(A) True
(B) False
Answer
Answer: (A) True
5. Photodiodes operate by absorption of photons or charged particles and generate a flow of current in an external circuit,……….. to the incident power. The light is absorbed ……….with distance and is ………..to the absorption coefficient.
(A) Proportional, exponentially, proportional
(B) Proportional, logarithmically, inversely proportional
(C) Inversely proportional, exponentially, unrelated
Answer
Answer: (A) Proportional, exponentially, proportional
6. What is the reason phototransistor produces more current than a photodiode?
(A) A wider spectrum is accepted by the phototransistor than the photodiode
(B) The current produced by photons is amplified by the hfe of the transistor
(C) The phototransistor can heavily doped than the photodiode
(D) At low light conditions, a photodiode is used.
Answer
Answer: (C) The current produced by photons is amplified by the hfe of the transistor
7. In a photodiode, when there is no incident light, the reverse current is almost negligible and is called
(A) Zener current
(B) Dark current
(C) Photocurrent
(D) PIN current
Answer
Answer: (B) Dark current
8. Compared to a photo-diode, which of the listed advantages and disadvantages would be expected of a phototransistor
(A) Faster response and greater sensitivity
(B) Faster response and less sensitivity
(C) Slower response and greater sensitivity
(D) Slower response and less sensitivity
Answer
Answer: (C) Slower response and greater sensitivity
9. When a diode is forward biased, the recombination of free electron and holes produce
(A) Heat
(B) Light
(C) Radiation
(D) All the above
Answer
Answer: (D) All the above
10. The width of the depletion region is
(A) Directly proportional to the doping
(B) inversely proportional to the doping
(C) Independent of doping
(D) None of the above
Answer:
Answer
Answer: (B) inversely proportional to the doping