Question

Assertion (A) $Si$ and $GaAs$ are the preferred materials for solar cells.
Reason (R) Both these materials have energy band gaps much below the energy level corresponding to the maximum solar irradiance ln the solar spectrum.
The correct answer is

• A. (A) is correct but (R) is incorrect.
• B. Both (A) and (R) are correct and (R) is the correct explanation of (A).
• C. Both (A) and (R) are correct but (R) is not the correct explanation of (A).
• D. Both (A) and (R) are incorrect.

Answer 1

Answer: (A)

The energy band gap of Si is $1.14\, eV$ and GaAs is $1.42 \,eV$.
Both Si and GaAs are used to make solar cells. In visible spectrum, energy is vary from about $3 eV$ on the violet side to $1.5 eV$ on red side, so visible light can make solar energy.
But radiowaves, microwaves and Infrared waves has less photon energy than the band gap of $Si$ and GaAs.
Hence, the assertion is correct but reason is wrong. Therefore, the correct option is (a)