The material suitable for making a solar cell is

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Photodiodes are preferably operated in reverse bias condition for light intensity measurement.
Reason $R$: The current in the forward bias is more than the current in the reverse bias for a $p-n$ junction diode.
In the light of the above statements,choose the correct answer from the options given below:

If the energy gap of a semiconductor used for the fabrication of an $LED$ is nearly $1.9 \ eV$, then the color of the light emitted by the $LED$ is

$A$ photodiode is fabricated from a semiconductor with a bandgap of $2.5 \ eV$. Can it detect a wavelength of $6000 \ \mathring{A}$?

The $I-V$ characteristic of an $\text{LED}$ is $:$

With increasing biasing voltage of a photodiode,the magnitude of photoelectric current