problem 1) Answer the following problems.
a) prepare down different polarization mechanisms in dielectrics?
b) Iron is a ferromagnetic material but a piece of iron does not ordinarily behave as a magnet. Describe.
c) Describe the meaning of stimulated emission.
d) prepare down the differences between step-index and graded-index fibers.
e) What is the electric flux through a closed surface surrounding an electric dipole? Describe.
f) Is the earth an inertial frame? If not, why?
g) prepare the Bragg's equation for X-ray diffraction and describe the meaning of various symbols in it.
h) What is the method of pumping in a Ruby laser?
i) State the conditions which a physically acceptable wave-function should obey.
j) prepare down some significant changes that occur in substances when they change from their normal state to the superconducting state.
problem 2)a) prepare down the four Maxwell's equations in differential form. describe the significance of each. Describe Maxwell's modification of Ampere's law.
b) Dielectric constant of a gas at NT.P. is 1.00074. If the gas is held in an external field of 3 x 104V/m, compute the dipole moment of each atom of the gas.
problem 3)a) What are the distinctive characteristics of ferromagnetism? Describe the domain theory of ferromagnetism.
b) The magnetic susceptibility of silicon is -4.2x10-6. Determine its magnetization and the magnetic flux density when it is placed in magnetic field of strength 1.2x105 A/m.
problem 4)a) What are Einstein's coefficients? Describe their meaning and derive the relation between them.