Sunday, October 11, 2009

IIT JEE Physics Final Revision Set 5

Light from a discharge tube containing hydrogen atoms falls on the surface of a piece of sodium. The kinetic energy of the fasted photoelectrons emitted from sodium is 0.73 eV. The work function for sodium is 1.82 eV.


1. the energy of the photons causing the photoelectric emission.
2. the quantum numbers of the two levels involved in the emission of these photons.
3. the change in the angular momentum of the electron in the hydrogen atom in the above transition.
4. the recoil speed of the emitting atom assuming it to be at rest before the transition. (Ionizatin potential of hydrogen is 13.6 eV.)

5.A plant observed by an astronomical refracting telescope having an objective of focal length 16 m and an eyepiece of focal length 2 cm.

a. The distance between the objective eye piece is 16.02 m.
b. The angular magnification of the planet is -800.
c. The image of the planet is inverted.
d. The objective is larger than the eyepiece.

Source; JEE 1992 paper

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