Consider the following statements:
A. The junction area of solar cell is made very narrow compared to a photodiode.
B. Solar cells are not connected with any external bias.
C. LED is made of lightly doped p-n junction.
D. Increase of forward current results in continuous increase of LED light intensity.
E. LEDs have to be connected in forward bias for emission of light.
Choose the correct answer from the options given below:
Answer: (A) B, E only
- A: A solar cell needs a **large** junction area to collect as much sunlight as possible. Wrong.
- B: A solar cell generates its own emf; no external bias is applied. Correct.
- C: LEDs are made from **heavily** doped p-n junctions. Wrong.
- D: Light intensity rises with forward current only up to a point, after which it saturates and then falls. Wrong.
- E: Light is emitted when electrons and holes recombine, which needs forward bias. Correct.
B, E only.
Solution by Sreeraj P, M.Sc Physics