Photodiodes are used in character recognition circuit.

Name the optoelectronic device used to detect optical signal

Three photo diodes $D1, D2$ and $D3$ are made of semiconductors having band gaps of $2.5\mathrm{eV}, 2\mathrm{eV}$ and $3\mathrm{eV}$, respectively. Which ones will be able to detect light of wavelength $600 nm$ ?

Given Planck constant is $h=6.62\times {10}^{-34} m^2 kg s^{-1}$,speed of light $c=3\times {10}^{8 }m{s}^{-1}$

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 statement, choose the correct answer from the options given below :

Name the optoelectronic device which convert optical radiation into electricity.

With reference to semiconductor devices, define a $p$-type semiconductor and a Zener diode. What is the use of Zener diode?

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R

Assertion A: Photodiodes are used in forward bias usually for measuring the light intensity.

Reason R: For a $p-n$ junction diode, at applied voltage $V$ the current in the forward bias is more than the current in the reverse bias for $\left|V_z\right|>\pm V\ge \left|V_0\right|$ where $V_0$ is the threshold voltage and $V_z$ is the breakdown voltage.

In the light of the above statements, choose the correct answer from the options given below

The forward characteristic curve of a junction diode is shown in the figure :

Calculate the resistance of the diode at

(i) $V=0·5 V$

(ii) $I=60 mA$

What is the advantage of an LED bulb over filament bulb?

Two $p$ - $n$ photodiodes are fabricated from semiconductors with band gap of $2.8\mathrm{eV}$ and $2.6\mathrm{eV},$ respectively.

Choose the correct statement from the following.