Past JEE Objective Questions Modern Physics - Part 2

1987

23. Four physical quantities are listed in column I. Their possible values are listed in column II in a random order. Match them.

ColumnI ----------------------Column II

a. Thermal energy of air----------e. 0.02 eV
molecules at room ----------------
temperature

b. Binding energy of--------------f. 2 eV
heavy nuclei per------------------
nucleon

c. X-ray photon energy-----------g. 1 keV

d. Photon energy of--------------h. 7 meV
visible light


24. Photoelectric effect supports quantum nature of light becasue

a. there is a minimum frequency of light.

b. the maximum kinetic energy of photoelectrons depends only on the frequency of light and not on its intensity.

c. even when the metal surface is fairly illuminated, the photoelectrons leave the surface immediately.

d.electric charge of the photoelectrons is quantized.


25. During a negative beta decay

a.an atomic electron is ejected.
b. an electron which is already present within the nucleus is ejected.
c. a neutron in the nucleus decays emitting an electron.
d. a part of the binding energy of the nucleus is converted into an electron.

26. During nuclear fusion reaction;
a. a heavy nucleus breaks into two fragments by itself.
b. a light nucleus bombarded by thermal neutrons breaks up.
c. a heavy nucleus bombarded by thermal neutrons breaks up.
d. two light nuclei combine to give a heavier nucleus and possibly other products.