Calicut University 2006 M.Sc Physics PHY204- ELECTRODYNAMICS - Question Paper
SECOND SEMESTER M.Sc. DEGREE EXAMINATION, AUGUST 2006
Physics
PHY. 204- ELECTRODYNAMICS
(2003 admissions)
C 17064 (Pages : 2) Name.....................................
. Reg. No.................................
SECOND SEMESTER M.Sc. DEGREE EXAMINATION, AUGUST 2006
Physics
Phy. 204ELECTRODYNAMICS (2003 admissions)
Time : Three Hours Maximum : 80 Marks
Section A
Answer any five questions.
Each question carries 4 marks.
1. ive Maxwells equation for time harmonic fields in point form and integral form.
(2 + 2 = 4 marks)
2. /State and explain the boundary conditions for the tangential component of E and the normal component of B.
(4 marks)
3. Show that the plane wave solutions to Maxwells equation in free space are transverse waves.
~ (4 marks)
4. Briefly describe the nature of propagation of electromagnetic waves in a conducting media.
~ 1 " (4 marks)
5. JpJxJjlain the advantages and disadvantages of co-axial cables and two wire transmission lines.
(2 + 2 = 4 marks)
6.Define standing wave ratio. Obtain the relation between standing wave ratio and reflection coefficient.
7. 'jSxplain what do you mean by Debye shielding. (4 marks)
8. What are Aliven waves ? Give expression for Alfven wave velocity. (2 + 2 = 4 marks)
[5 x 4 = 20 marks]
Section B
Answer all questions.
Each question carries 20 marks.
9. /(a) Discuss the theory of reflection and refraction of electromagnetic waves at a plane interface
between two dielectrics.
ifo) Write down the wave equations and obtain their solutions.
(10 + 10 = 20 marks)
Or
10. (a) What are wave-guides ? Distinguish between metallic and dielectric wave guides. ,
(b) Describe the features of a dielectric wave guide in the shape of a circular cylinder placed in an external non-permeable medium of dielectric constant e0.
(10 + 10 = 20 marks) Turn over
2 C 17064
10. }s the Maxwells equations Lorentz invariant ? What is field tensor ? Express the equations in ' electrodynamics in tensor notation.
(2 + 3 + 15 = 20 marks)
Or
(a) What is Poynting vector ? Obtain expression for the Poynting vector.
(b) Derive the equation of motion of a charged particle in an electromagnetic field.
(10 + 10 = 20 marks) [2 x 20 = 40 marks]
Section C
Answer any two questions.
Each question carries 10 marks.
11. Assuming the Lorentz transformation equations for electromagnetic field, find the expression for the magnetic field due to a point charge in uniform motion.
12. Verify that the Poynting vector is invariant under the transformation E = E cos<|> + B sin<|> B' = E sin <j) + B cos <|>.
What is physical significance of the transformation when <|> = 7i / 2 ?
13. The electric field to free space iff given by g = 5cos (108 t + p*) d
is- m
14. Find :
(a) The direction of wave propagation.
(b) Calculate (3 and the time it takes to travel a distance of 7J2.
(c) Ey components at t = 0, T/4 and T/2.
15. An air transmission line has characteristic impedance of 70 Q and phase constant of 3 rad/m at 100 MHz. Calculate the inductance/m. and the capacitance/m. of the line.
(2 x 10 = 20 marks)
|
Attachment: |
| Earning: Approval pending. |
