Match List – I with List – II.
| List - I | List - II | ||
|---|---|---|---|
| A. | Solar cell | I. |  |
| B. | Forward bias of p-n diode | II. |  |
| C. | Reverse bias of p-n diode | III. |  |
| D. | Photo diode | IV. |  |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A-IV, B-I, C-III, D-II
Each device has its own region of the I-V plane: forward bias is the first quadrant, reverse bias the third, and a solar cell, which delivers power, works in the fourth.
(A) Solar cell — this matches (IV). A solar cell is used without an external bias and supplies power, so its I-V curve lies in the fourth quadrant, with the short-circuit current and the open-circuit voltage as its end points on the two axes.
(B) Forward bias of p-n diode — this matches (I). In forward bias the current is very small until the barrier is overcome and then rises steeply with the voltage, giving a curve in the first quadrant.
(C) Reverse bias of p-n diode — this matches (III). In reverse bias the current is a very small, almost constant reverse saturation current until the breakdown voltage is reached, where it suddenly increases.
(D) Photo diode — this matches (II). A photodiode is operated in reverse bias, and its reverse current depends on the intensity of the light falling on it, so its curve lies in the third quadrant and the current grows in magnitude with illumination. Of the two third-quadrant curves, (III) is the ordinary diode with its flat saturation current, so (II) is the photodiode.
Note: This question is from the pre-rationalised NCERT book (2022-23). The topic was removed from the latest NCERT book (2026-27), and it also appears to be out of the CUET 2026 syllabus.
NCERT (Pre-rationalised edition, 2022-23):
Optoelectronic Junction Devices – “… A Photodiode is again a special purpose p-n junction diode fabricated with a transparent window to allow light to fall on the diode. It is operated under reverse bias.”
Optoelectronic Junction Devices – “… Note that the I – V characteristics of solar cell is drawn in the fourth quadrant of the coordinate axes. This is because a solar cell does not draw current but supplies the same to the load.”