Which of the following statements is $NOT$ correct in the case of an $LED$?

Assertion: $A$ $p-n$ junction with reverse bias can be used as a photo-diode to measure light intensity.
Reason: In a reverse bias condition,the current is small but is more sensitive to changes in incident light intensity.

The photocurrent in a photodiode depends on

Consider a situation in which reverse biased current of a particular $P-N$ junction increases when it is exposed to light of wavelength $\lambda \le 621 \, nm$. During this process,enhancement in carrier concentration takes place due to the generation of hole-electron pairs. The value of the band gap is nearly (in $eV$):

What are the ideal materials for the fabrication of a solar cell? Give the criteria for their selection.

$A$ $CCD$ camera is fabricated using a semiconducting material having a band gap of $3 \ eV$. The wavelength of light it can detect is nearly (in $nm$)