Pondicherry University 2009 B.Tech Electronics and Communications Engineering , 2010/ Physics - Question Paper

part A-(10*2=20 MARKS)

1. What are transverse ultrasonic waves?
2. What do you mean by acoustics of building?
3. What is an air wedge?
4. What is a circularly polarised light?
5. elaborate the characteristic features of a laser beam?
6. Why do we use 1.55 micro meter wavelength in fiber optical communication?
7. State Heisenberg's uncertainty principle.
8. The position of an electron in an atom is located within a distance of 0.1 armstrong using a microscope. what is the certainty in the momentum of the electron located in this way?
9. elaborate prompt neutrons?
10. What is the function of a moderator in a nuclear reactor?


part B-(5*11=55 MARKS)

11. What is magnetostriction effect? discuss how are the ultrasonic waves produced using a magnetostriction oscillator?

(or)

12. Derive Sabine's mathematical relation for reverberation time.

13. discuss the construction and working of a Michelson's interferometer and hence, discuss how is it used to obtain the refractive index of a transparent layer.

(or)

14. discuss in detail the production of plane, circularly, and elliptically polarised lights.

(or)

15. discuss in detail the construction and working of a Nd:YAG laser with a suitable energy level diagram.

(or)

16. (a) Define:
(i) Acceptance angle and
(ii) Numerical aperture.
(b) A fibre has a core diameter of six micrometer and its core refractive index is 1.45. The refractive index of the cladding is 1.448. Determine the maximum number of modes allowed to propagate through the fibre , if the wavelength of light used is one micrometer.

17. Derive the Schroedinger time dependent wave formula and hence find time independent wave formula.

(or)

18. discuss the application of Schroedinger's wave formula using 1 dimensional potential well issue.

19. What is meant by nuclear fusion? discuss the nuclear fusion reaction which takes place in the sun and stars.

(or)

20. discuss the construction and working of a Pressurised Water Reacter(PWR).

Earning:   Approval pending.