FREQUENCY
* WHAT IS FREQUENCY?
Frequencies can be described by calculating the number of waves passing through a fixed place in the given time period.
For Eg: If time taken by a wave to pass a place is half second than the frequency is 2/second.
The unit of frequency is HERTZ which is named in the honor of Heinrich Rudolph Hertz, a German Physicist.
Th abbreviation of frequency is Hz
* RELATIONSHIP BETWEEN FREQUENCY AND WAVELENGTH
The relation between frequency and wavelength is one of the defining characteristics for calculating speed of light. Wavelength is measured in meters.
The frequency of electromagnetic wave is multiplied with wavelength, it equals the speed of light.
SPEED OF LIGHT = FREQUENCY * WAVELENGTH
* FREQUENCY OF LED LIGHTS
The colour of LED depends on its frequency in ELECTROMAGNETIC SPECTRUM.
RED LED
1. Red light operates at a wavelength of 633 nanometers approx.
2. These are used in electronic displays, indicator lights and in many other applications.
3. This is made up of Indium Gallium Aluminium Phosphide.
FREQUENCY OF RED LED=SPEED OF LIGHT/ WAVELENGTH =(3 x 10^8 ) ÷ (633 x 10^-9)
FREQUENCY= 474 terahertz (THz)
BLUE LED
1. Blue light operates at a wavelength of 470 nanometers approx.
2. These are used in everyday electrical appliances as they are cheap enough.
3. It is made of Silicon carbide and gallium nitride.
FREQUENCY OF BLUE LED=SPEED OF LIGHT/ WAVELENGTH =(3 x 10^8 ) ÷ (470 x 10^-9)
FREQUENCY= 638 terahertz (THz)
GREEN LED
1. It produces light at a wavelength of 560 nanometers approx.
2. The invention of green led paved a way for the generation of white Led light sources.
FREQUENCY OF RED LED=SPEED OF LIGHT/ WAVELENGTH =(3 x 10^8 ) ÷ (633 x 10^-9)
FREQUENCY= 474 terahertz (THz)
BLUE LED
1. Blue light operates at a wavelength of 470 nanometers approx.
2. These are used in everyday electrical appliances as they are cheap enough.
2. It is made of Silicon carbide and gallium nitride.
FREQUENCY OF RED LED=SPEED OF LIGHT/ WAVELENGTH =(3 x 10^8 ) ÷ (560 x 10^-9)
FREQUENCY= 535 terahertz (THz)
WHITE LED
1. This LED consists of components of red, green and blue light. So it does not have any particular wavelength. It is a mixture of other three frequencies.
2. Cheap energy-efficient lights can be developed with white led so it is used in a variety of setting like street lights, desk lights.
