Profile
Settings
Refer your friends
Sign out
If you want to learn about the wave theory of light, Young’s Double Slit Experiment is a great place to start. This experiment was first conducted by Thomas Young in 1801, and it helped to firmly establish the wave theory of light. The basic principle behind this experiment is that light behaves as a wave when it travels through space. In this blog post, we will discuss the results of the double-slit experiment and how they support the wave theory of light.
Discover Unacademy UPSC Offline Centres in the following locations
What Is Young’s Double Slit Experiment?
In 1801, Thomas Young performed an experiment that would help disprove the wave theory of light. The wave theory of light had been the dominant explanation for how light travels since Isaac Newton proposed it in the late 1600s. However, there were some inconsistencies with the wave theory that Young’s experiment helped to reveal.
Young’s Double Slit Experiment is a coherent light source, such as a laser, that is shone on a screen with two slits cut into it. What happens is that coherent light waves passing through the two slits interfere with each other, creating a wave-like interference pattern on the screen behind the slits.
What Happens In Young’s Double Slit Experiment?
When coherent light shines on a screen with two slits, it produces a characteristic interference pattern of dark and bright bands. The distance between the bright bands is directly related to the wavelength of the light. This discovery supported the wave theory of light over Newton’s particle theory and showed that light behaves as a wave.
What Is Young’s Double Slit Formula?
Young’s Double Slit formula or equation is:
d= (λ *D)/w
Where:
d = distance between slits
λ = wavelength of light
D = distance from slits to the screen
w = width of slit
How does it work?
The coherent light waves (all with the same wavelength) passing through the two slits interfere with each other. This interference creates a series of fringes (alternating light and dark bands) on the screen. The distance between the slits (d) and the width of the slits (w) determine the wavelength of light that will create constructive interference (bright fringes).
The distance from the slits to the screen (D) determines how far apart these fringes will be.
This experiment is often used to demonstrate the wave nature of light. The key to this experiment is that the coherent light waves must have the same wavelength. This can be accomplished by using a laser or monochromatic (single wavelength) light source.
If the light source is not coherent or monochromatic, then the fringes will be blurred and no interference pattern will be observed.
What Is Constructive Interference For Double-Slit?
The constructive interference for double-slit is when the coherent waves meet and are in phase with each other. The wavelength is the distance between two successive peaks of a wave. When the coherent waves have the same wavelength, they will be in phase with each other and will produce constructive interference.
What Is Destructive Interference Of Double-Slit?
The destructive interference for double-slit is when the coherent waves meet and are out of phase with each other. The wavelength is the distance between two successive peaks of a wave. When the coherent waves have different wavelengths, they will be out of phase with each other and will produce destructive interference.
Conclusion
The wave theory of light was able to explain the results of Young’s double-slit experiment because it showed that coherent light waves are able to produce an interference pattern. The wavelength of the light determined the spacing between the fringes in the interference pattern. This was a very important discovery because it helped to support the wave theory of light and showed that light could exhibit wave-like behaviour. If you want to learn more about Young’s double-slit experiment, or other experiments that have helped to shape our understanding of light, be sure to check out the resources below. Thanks for reading!
