00:01
Let's say two coherent sources are there, ok, and they are emitting the wave.
00:08
Ok, let's say and the amplitudes are a1, a2 and intensities are i1 and i2.
00:19
Ok, so these two are, let's say, coherent sources.
00:26
Ok, so resultant amplitude, we can say resultant amplitude a equal to, we can write a1 square plus a2 square plus 2a1a2 cos phi, where phi is the phase difference.
00:59
Ok, and intensity, resultant intensity, i'm writing it clearly, intensity, let's say, i equal to what you can write, i1 plus i2 plus 2 root over i1 i2 and it is cos phi.
01:35
Ok, we can write like this.
01:38
Ok, now let us talk about constructive interference.
01:45
Ok, so here i'm writing constructive interference, interference.
02:02
Ok, so actually in this case, two waves meet, ok, and they collide and we can say combine.
02:30
Ok, we can say like this, two waves meet, they collide or we can say then they collide and combine.
02:40
Ok, so in this case, we can say, in this case, the resultant amplitude and intensity are maximum.
03:06
Ok, so a max in this case is a1 plus a2 and i max equal to root over, we can say like this, root over i1 plus root over i2 whole square.
03:36
Ok, we can write like this.
03:38
So, if we talk about the position, so cos phi equal to plus 1, ok, that mean phi equal to 0, 2 pi, 4 pi, dot, dot, dot, we can say 2n pi.
03:57
Ok, that means del x, that is the, we can say the path difference, path difference, that is the del x equal to, we know, phase difference into lambda by 2 pi...