00:01
Other everyone, we are going to understand this question here given in the question, if the kinetic energy of photon is zero, if the kinetic energy of photon is zero, kinetic energy of photon is zero, then wavelength lambda is equal to wavelength lambda is equal to 490 nanometer.
01:01
Or we can write 490 into 10 to the power minus 9 meters and work function of material work function of material that is represented by 5 which we have to find now using photoelectric equation now using photoelectric equation photoelectric equation photoelectric equation so we can write 5 is equal to xc upon lambda now substituting the value in this so from this we can write 5 is equal to value of h that is 6 .6 into 10 to the power minus 34 value of c that is 3 into 10 to the power 8 upon value of lambda that is 490 into 10 to the power minus 9 joules now doing further calculation so we will get 0 .04 into 10 to the power minus 17 june.
02:37
So after doing further calculation, we will get 5 is equal to 4 into 10 to the bar minus 9.
02:47
So 10 to 10 to the 1 minus 19 joules.
02:54
This is the required value of work function of the material.
02:59
Now in the part b, it is given that if wavelength of the photon, if new wavelength of photon, new wavelength of photon, lambda dash is lambda dash that is 420 nanometer.
03:30
Or we can lie, lambda dash is equal to 420 into 10 to the core minus 9 meter.
03:38
Let the required stopping potential be v.
03:43
Let the required stopping potential...