CBSE Class 12 Physics Chapter-11 Important Questions – Free PDF Download
Free PDF download of Important Questions with Answers for CBSE Class 12 Physics Chapter 11 – Dual Nature of Radiation and Matter 1 Mark Questions prepared by expert Physics teachers from latest edition of CBSE(NCERT) books only by CoolGyan to score more marks in CBSE board examination.
CBSE Class 12 Physics Chapter-11 – Dual Nature of Radiation and Matter
CBSE Class 12 Physics Important Questions Chapter 11 – Dual Nature of Radiation and Matter
1 Mark Questions
1.Calculate the energy associated in eV with a photon of wavelength 
?
Ans. 
E = 3.09 eV
2.Mention one physical process for the release of electron from the surface of a metal?
Ans. Photoelectric emission.
3.The maximum kinetic energy of photoelectron is 2.8 eV. What is the value of stopping potential?
Ans. 
4. Calculate the threshold frequency of photon for photoelectric emission from a metal of work function 0.1eV?
Ans. 
5.Ultraviolet light is incident on two photosensitive materials having work function
and 
( > ). In which of the case will K.E. of emitted electrons be greater? Why?
Ans. 
If > thus K.E. will be more for second surface whose work function is less.
6.Show graphically how the stopping potential for a given photosensitive surface varies with the frequency of incident radiations?
Ans. 
– threshold of frequency
or cut off frequency
7. How does the stopping potential applied to a photocell change if the distance between the light source and the cathode of the cell is doubled?
Ans. Stopping potential does not depend on the intensity of the light source which changes due to the change in distance from the light source.
8.On what factor does the retarding potential of a photocell depend?
Ans.It depends upon the frequency of the incident light
9.Electron and proton are moving with same speed, which will have more wavelength?
Ans. Since 
so electron being lighter will have more wavelengths