1. A beam of ultraviolet radiation, with frequency of 2.29x10 15 Hz is directed
ID: 1565374 • Letter: 1
Question
1. A beam of ultraviolet radiation, with frequency of 2.29x1015 Hz is directed on a clean metal surface. The work function of the metal is 3.80 eV. Calculate the maximum kinetic energy for an electron dislodged from the surface by the radiation.
2.
Which of the following statements are true for the photo-electric effect? (For each statement select T True, F False).
A) The maximum energy of the ejected electrons is proportional to the intensity of the incoming photons.
B) The frequency of the photons must be larger than a certain minimum value in order to eject electrons from the metal.
C) The maximum energy of the ejected electrons varies linearly with the frequency of the incoming photons.
D) The maximum energy of the ejected electrons is proportional to the velocity of the photons.
Explanation / Answer
1) use Einstein's photo equation
E = Wo + KE_max (here E is energy of photon and Wo workfunction of the metal)
KE_max = E - Wo
= h*f - Wo
= 6.626*10^-34*2.29*10^15 - 3.8*1.6*10^-19
= 9.09*10^-19 J or 5.68 eV
2)
A) False
B) True
C) True
D) False
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.