Question

Draw the $V - I$ characteristic of LED. State two advantages of LED lamps over conventional incandescent lamps?

Answer 1

Hint:As we know that the LED stands for light emitting diode. The working principle of the diode is when an electron jumps from higher energy level to the lower energy level then emission of light occurs.

Complete step by step answer:
The current versus voltage graph is shown in the figure below:

One of the important aspects of the light emitting diode is the color as shown in the figure by different wavelengths. The very first color used was red. As we know that diode is forward biased (conduct only in one direction) and the electron and hole move constantly across the junction and the electron combines with the holes in this process thus emitting light.
The V-I characteristic is nonlinear as seen above. The flow of current is less until the forward voltage is reached above which the current increases exponentially with increase in voltage. The colour of the LED is determined by the bandgap of semiconductor and forward voltage.
There are several advantages of the light emitting diode such as stated below:
1. The cost is less: The cost of the LEDs are low as compared to the other commercial bulb which is the main advantage of LED.
2. Energy consumption is $90{\raise0.5ex\hbox{$\scriptstyle 0$}
\kern-0.1em/\kern-0.15em
\lower0.25ex\hbox{$\scriptstyle 0$}}$ lesser as compared to bulbs.

Note:
As we know that the V-I characteristic of LEDs depends on the wavelength of the color of LED. LEDs are one of the most exciting technologies in the light industry. They are compact and have long lasting life as compared to another bulb.