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

$A$ $p-n$ photodiode is fabricated from a semiconductor with a band gap of $2.8 \; eV$. Can it detect a wavelength of $6000 \; nm$?

$A$ photodetector is made from a semiconductor $In_{0.53}Ga_{0.47}As$ with $E_g = 0.73 \, eV$. What is the maximum wavelength,which it can detect in $nm$?

Which of the following statements is not correct in the case of light emitting diodes?

Consider the following statements $A$ and $B$ and identify the correct answer:
$A$. For a solar-cell,the $I-V$ characteristics lies in the $IV$ quadrant of the given graph.
$B$. In a reverse biased $pn$ junction diode,the current measured in $(\mu A)$ is due to majority charge carriers.

Consider the following statements $:$
$A.$ The junction area of a solar cell is made very large compared to a photodiode.
$B.$ Solar cells are not connected with any external bias.
$C.$ $\text{LED}$ is made of heavily doped $p-n$ junction.
$D.$ Increase of forward current results in continuous increase of $\text{LED}$ light intensity up to a saturation point.
$E.$ $\text{LED}$ must be connected in forward bias for the emission of light.
Which of the following statements are correct?