The symbolic representation of a photodiode is:

In an $LED$,visible light is produced by:

$A$ 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 $nm$?

What kind of $p-n$ junction diode does not require any kind of bias?

$A$ Light Emitting Diode $(LED)$ has a voltage drop of $2\,V$ across it and passes a current of $10\,mA$ when it operates with a $6\,V$ battery through a limiting resistor $R$. The value of $R$ is.........$k\,\Omega$.

In optical fiber communication, an $APD$ semiconductor is used for: