00:01
In this problem, it is given that consider the two waves shown here which we will consider to represent two electromagnetic radiations.
00:14
Right.
00:15
So here is two waves given like this.
00:19
And it is asked that for the first part, what is the wavelength of the wave a and of wave b? and secondly, it is asked what is the frequency of wave a and of wave b.
00:31
And thirdly, it is asked to identify the region of electromagnetic spectrum to which waves a and b belongs to.
00:42
Right.
00:42
So here, what are the observation? we know that one, this, the wavelength of this first wave is this, right? so this means that this is half, right? so this is one wave again.
01:02
We can say this is another wave.
01:05
Then again this is another wave right this is a cycle which is repeating in this way right so this is also repeating but now only here what we are getting is okay all right is it should be like this this is this is in wave it is like this right this i'm sorry i have drawn in this way this should be drawn in this way right so this is somewhat in this way right so this is half half wave right this is not full wave so can we say there are how many waves one one two three four and four point five right so this will be what this will be point five half of the wave right so this is the observation we got to know now we need to find wavelength then frequency right so wavelength of wave a will be what so for part a wavelength of wave a is given by you can say there are 4 .5 waves between 1 .6 into 10 to the power minus 7 meter.
03:12
So lambda will be equal to what? lambda will be equals to length of the wave divided by number of you can say how many times it is.
03:30
So this is 4 .5 waves number of waves.
03:36
So this will give us 3 .55 into 10 to the power minus 8 meter.
03:44
This is wavelength for wave a.
03:51
Now the wavelength for the wave b will be what? so here only two waves are present.
04:08
This is one cycle and this is another cycle.
04:14
So for wave a, there is 4 .5 waves.
04:18
Right but here for b here two cycles are concerned right so this is the we are asked for full wave right for this much meter 1 .6 into 10t power minus 7 meters right so what we will do now we will say wavelength of wave b there are how many waves two waves between 1 .6 into 1 .6 into 1 .6 in 3 to 10 to the power minus 7 meters, right? so, therefore, lambda will be equals to distance upon number of waves, right? so this will give us actual wavelength.
05:23
So wavelength is nothing but wavelength is something which is which makes one cycle.
05:32
Wave length of the one cycle and after that all that cycle are repeating in the same way.
05:38
Right so that's why we are divided by two because here there are two waves and after this we know that after this point this wave is repeating and there are two waves similar right so this will be divided by two here again so we will get lambda equals to 8 .0 into 10 to the power minus 8 meter so this is a wavelength for wave b...