The I-V characteristic of an LED is represent | vedclass

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(B) An $LED$ is a forward-biased $p-n$ junction diode that emits light when current flows through it. The energy of the emitted photons is given by $E

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(B) An $LED$ is a forward-biased $p-n$ junction diode that emits light when current flows through it. The energy of the emitted photons is given by $E = h
u = \frac{hc}{\lambda}$. Since $E = eV$,where $V$ is the threshold voltage,we have $eV = \frac{hc}{\lambda}$,which implies $V \propto \frac{1}{\lambda}$. Since the frequency $
u$ is related to wavelength $\lambda$ by $
u = \frac{c}{\lambda}$,we have $V \propto 
u$. Higher frequency light (like blue) requires a higher threshold voltage compared to lower frequency light (like red). Therefore,for a given current,the voltage required increases in the order $R < Y < G < B$. The graph that correctly depicts this forward-biased characteristic where the threshold voltage increases with frequency is the one where the curves shift to the right as we move from red to blue.

The $I-V$ characteristic of an $LED$ is represented by which of the following graphs?

Similar Questions

Assertion: $A$ $p-n$ junction with reverse bias can be used as a photo-diode to measure light intensity.
Reason: In a reverse bias condition,the current is small but is more sensitive to changes in incident light intensity.

The given characteristic curve is related to which electronic device?

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.

Identify the incorrect statement.

Conductivity of a photodiode starts changing only if the wavelength of incident light is < 660 \, nm. The band gap of the photodiode is found to be $\left(\frac{x}{8}\right) eV$. The value of $x$ is: (Given, $h=6.6 \times 10^{-34} \, Js, c=3 \times 10^8 \, m/s, e=1.6 \times 10^{-19} \, C$)

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