Punjab Technical University 2010-1st Sem B.Tech B Tech ester, , Physics , Regular , - Question Paper

Time: three Hours
Maximum Marks: 60

Instruction to Candidates:
1) Section- A is Compulsory.
2) Attempt any 5 ques. from Section- B & C
3) choose at lowest 2 ques. from part - B & C

part – A [Marks 2*10=20]

Q1)a) What is the differential form of Gausss law?

b) What do you mean by ferromagnetic domain?

c) What is the fundamental principle of a hologram?

d) What do you understand by Single mode and Multimode fibre?

e) A stationary body explodes into 2 fragment every of rest mass one Kg that move apart at speeds of 0.6c relative to the original body. obtain the mass of the original body.

f) 2 photons approach every other, what is their relative velocity.

g) An X-ray tube is operated at25 kV. obtain the minimum wavelength of X-rays emitted from it.

h) What is de-Broglie hypothesis?
i) What is Compton effect?
j) What is Meissner effect?

part – B [Marks: eight Each]

Q2) (a) Write down Maxwells equations and discuss their physical significance.

(b) Show that the velocity of plane electromagnetic wave in free space is c=1/ue

Q3) a) elaborate ferrites? How are they superior to ferromagnetic materials? Write a short note on magnetostriction.

b) describe magnetic susceptibility & relative magnetic permeability and establish the relationship ranging from them.

Q4)a)Discuss with suitable diagrams the principle, construction and working of Helium-Neon Laser. discuss the role of Helium atoms in this laser. How is it superior to a Ruby-laser?

b)What are the differences ranging from the terms spontaneous and stimulated emission?

Q5) (a) discuss the difference ranging from a step-index fibre and graded index fibre.

(b) What is meant by acceptance angle for an optical fibre? Show how it is related to numerical aperture.

part – C [Marks: eight Each]

Q6)a) What was the objective of conducting the Michelson-Morley experiment? define the experiment. How is the negative outcome of the experiment interpreted?

b)Show that the rest mass of a particle is provided by p=m2c2-T2/2Tc2,
P and T denote the momentum and kinetic energy of the particle.

Q7) (a) What is Moseleys law? How can it be discussed on the basis of Bohrs theory? What is its importance?

(b) How will it affect the cut off wavelength of X-rays if the separation ranging from the cathode and target is doubled?

Q8) (a) What is Borns probability interpretation of wave-function?

(b) What is the difference ranging from phase and group velocities? Show that the de Broglie group velocity associated with the wave packet is equal to the velocity of the particle.

Q9) (a) discuss the difference ranging from the kind I and kind II superconductors.

(b) provide the salient features of BCS theory of superconductors.

(c) Superconductors are a perfect diamagnet. discuss.

Earning:   Approval pending.