The bandgap of the material of a photodiode is $2.0 \ eV$. What is the minimum frequency of radiation that this material can absorb?

Conductivity of a photodiode starts changing only if the wavelength of incident light is < 660 \, nm. The band gap of the photodiode is found to be $\left(\frac{x}{8}\right) eV$. The value of $x$ is: (Given, $h=6.6 \times 10^{-34} \, Js, c=3 \times 10^8 \, m/s, e=1.6 \times 10^{-19} \, C$)

The given graph represents $V-I$ characteristic for a semiconductor device. Which of the following statements is correct?

$(i)$ Name the type of diode whose characteristics are shown in figure $(a)$ and figure $(b)$.
$(ii)$ What does the point $P$ in figure $(a)$ represent?
$(iii)$ What do the points $P$ and $Q$ in figure $(b)$ represent?

An $LED$ (Light Emitting Diode) is constructed from a $p-n$ junction based on a certain $Ga-As-P$ semiconducting material whose energy gap is $1.9\, eV$. What is the wavelength of the emitted light?

The photodiode is made of a material with a band gap of $2.0\, eV$. The minimum frequency of the radiation that can be absorbed by the material is nearly