00:01
Hello dear in this video we are going to talk about interference of light that is done by young's double slit experiment.
00:11
So look here please at the figure.
00:14
We have two slits.
00:15
They are separated by a distance a and the distance between the screen and the slits is capital d and there is a light of wavelength lambda.
00:30
That is incident on these two slits.
00:34
So of course we will observe here the interference pattern on our screen.
00:42
The question in this exercise is to choose which of the choices given will cause the fringes in the interference pattern to come close to each other.
00:58
In fact, we can solve this by by more than one way, i will explain here two ways actually to solve this problem.
01:09
So we can solve it by this formula, which is i equal lambda d over a, where i is called the inter fringe distance, which is the distance between two consecutive bright or two consecutive dark fringe.
01:26
It's given by i equal lambda d over a, and as i said, lambda is the way length, d is the distance here between the screen and the slits, and a is the distance between the two slits.
01:41
Pay attention learners that these symbols can change from one textbook to another, but don't worry because i'm explaining the meaning of each symbol in my formula that i am using it.
01:55
So we can use this formula to answer the question, or we can use this formula to answer the question, or we can use this formula to answer the question which is the position of the bright fringes in an interference pattern the position of bright fringes is given by this rule n lambda d over a for taking the first bright fringe for simplifying my solution or for making it easier i will consider the first bright fringe that corresponds to n equals to one so the rule will be y equal lambda d over a so we came up with the same formula okay now my target is to decrease i or to decrease why it's the same because once i decrease them the distance between the fringes will decrease so let me now look at these choices to check to check which of them will decrease in the first choice they told us that we are decreasing the slit separation distance which we call it a by decreasing a i will increase since they are inversely proportional as you can see so and it's not correct because it's not the thing i want i want to decrease i and not increase it so this is wrong let's move now to choice b.
03:34
In choice b they told us that we used red light instead of green light.
03:42
Let's check the wavelengths of red and green...
