For the emission of light,a light emitting diode $(LED)$ is:

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

To measure light intensity,we use:

In a $PN$ junction photocell,the value of the photo-electromotive force produced by monochromatic light is proportional to

$A$ solar cell is to be fabricated for efficient conversion of solar radiation to emf using material $A$. The solar cell is to be mechanically protected with the help of a coating using material $B$. If the band gap energy of materials $A$ and $B$ are $E_{A}$ and $E_{B}$ respectively,then which of the following choices is optimum for better performance of the solar cell?

The $V-I$ characteristics of an $LED$ are correctly shown by which graph?