00:01
In this question we have been given information and based on it we need to first find out that if frequency is increased what difference does it cause to the maximum kinetic energy of electrons and in the second part we need to find out the difference in work function.
00:14
So here it can be written that we know the formula that is hf and it is here equals to maximum kinetic energy and then it will be here we can say plus wa.
00:24
So here the wa values the work function for surface a.
00:28
So we can just rewrite this very expression as hf and then it will be here kinetic energy for the surface a and then it will be here work function for the surface a.
00:40
So here h is the plank constant, f is the frequency.
00:44
So we have here considered two surfaces.
00:47
One surface a is having the work function wa and there is another surface b which will be here having the value of kinetic energy to be here equals to this, that is k.
00:58
We can say k .e for b and then it will be here plus work function for b and hence from these two equations that we have written it can be here said that the maximum energy basically the maximum kinetic energy for electrons emitted from the surface a and b are here going to be k -e -a and k -e -b so if we subtract these two equations then here we are going to have it will be here zero and then it will be here k a sorry it is the kinetic energy for surface a minus it will be here kinetic energy for surface b and then it will be here plus work function for surface a minus it will be here work function for surface b so solving this very expression further we can write that difference in work function will be here like this and it is here going to be equal to the difference in kinetic energy and hence it can be here written as k dot a and then it will be here so with this very expression it can be here said that the frequency is independent of the, we can say, maximum kinetic energy.
02:07
So in the first part of this very problem we can say that the difference in maximum kinetic energy can be here shown like this and it is basically independent of frequency and it depends only on the work function right and since it is independent of frequency so changing the value of frequency will not affect the change in, we can say, the maximum kinetic energies.
02:33
So the value of maximum kinetic energy remains the same...