» CBSE Physics Electrons and Photons Expected Questions : Unit X : CBSE Sample Question Papers

CBSE Physics Electrons and Photons Expected Questions : Unit X Filed under: Class XII Physics Expected Question Short Answer Type Questions Q. 1. Discuss dual nature of radiations. Ans. Dual Nature of Radiation Answer Q. 2. Compare Compton effect and Photo-electric effect. Answer Q. 3. Find the de-Broglie wavelength associated with an electron accelerated under a potential difference of V volts. Answer Q. 4. Every metal has a definite work function. Why do photoelectrons not come out all with same energy if incident radiation is monochromatic ? Why is there an energy distribution of photoelectrons ? Answer Q. 5. For photoelectric effect in a metal, the figure shows the plot of cut off voltage versus frequency of incident radiations. Calculate (i) the threshold frequency ; (ii) the work function for given metal. Answer Q- 6. Quarks inside protons and neutrons are through to carry fractional charge + 2/3 e; - 1/3 e. Why do not they show up in Millikan’s oil drop experiment ? Answer Q. 7. A monoergic electron beam with electron speed of 5.20 x 106 ms-1 is subjected to a magnetic field of 1.30 X 10-4 T normal to beam velocity. What is the radius of the circle traced by the beam ? Given e/m for electron equals 1 76 X 1011 C kg-1 . Answer Pages: 1 2 3

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