A photodiode is fabricated with band gap of 3 eV. It can detect

The correct answer is Option (1) → Visible light

For detection of light by photodiode $E \leq \frac{h c}{\lambda}$

$3 \mathrm{eV} \leq \frac{12400}{\lambda}$

$\lambda \leq \frac{12400}{3} \Rightarrow \lambda \leq 4130 Å$

The photodiode can detect the light lying in visible region (partially) and of ultraviolet region.