The $I-V$ characteristics of a photodiode for different illumination intensities $I_1, I_2, I_3$ and $I_4$ are shown in the figure. Which of the following represents the maximum intensity?

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 $eV$):

In a $p-n$ junction solar cell,the value of photo-electromotive force produced by monochromatic light is proportional to the

$A$ photodiode is a device

$A$ photodetector is fabricated from a semiconductor with a band gap $E_g = 0.73 \, eV$. What is the maximum wavelength (in $nm$) it can detect?

For three circuit elements $A, B$ and $C$,following observations were made in lab:
$(a)$ element $A$ cannot conduct $d.c.$ but allows $a.c.$ through it.
$(b)$ element $B$ conducts both $AC$ and $DC$ but in one direction only.
$(c)$ Element $C$,when connected across $DC$,conducts only for one polarity and emits light whose intensity first increases and then decreases with increase in applied voltage.
The elements $A, B$ and $C$ are respectively identified as