Maharashi Dayanand University (MDU) 2010 B.Tech Electronics and Communications Engineering Physics - Question Paper
24003
B. Tech. 1st Semester F Scheme" Examination - December, 2010
PHYSICS-1
Paper: Phy-101-F
Time : Three hours ] [ Maximum Marks : 100
Before answering the questims, candidates shoidd ensure that they have been supplied the correct and complete question paper. No complaint in this regard, will be entertained after examination.
Note: Attempt five questions in all. Question No. 1 is compulsory and select one question from each Unit. All questions carry equal marks.
1. (c What do you mean by modal dispersion ?
(bj/'Discuss differences between Fraunhofer and Fresnel diffraction.
(c) What is meant by specific rotation ?
(d What are inverse Lorentz transformation equations ?
(e/f! the kinetic energy of a body is twice its rest mass'energy, find its velocity.
($/*What do you mean by population inversion ?
Fresnel's Biprism.
(fcO For a dielectric the value of dielectric constant is ' 1.329, calculate its electric susceptibility (%e).
(i) Calculate the minimum thickness of a quarter wave plate of calcite for X = 5460A, the
bifringence of the plate (jae (a0) being 0.172.
(0/why sound wave is easily diffracted but light will not diffract in daily life ? 2 x 10 = 20
UNIT-I
2. (a) Explain the formation of interference fringes in a
Michelson interferometer. Discuss its important applications. 15
(b)' A thin plate is introduced in the path of one of the
_________beams of light in Michelson interferometer and it
is found that 50 bands have crossed the line of observation. If wavelength of light is 5896 A and fj, = 1.4' determinethe thickness of the plate. 5
4. (a) jpescribe a Nicol's prisms, showing clearly how it
is constructed and what is its action. 15
(b) How we can produce plane polarized light from / circular polarized or elliptically polarized light ? Explain. 5
5. (a) Describe the principle, construction and working
of He - JNe laser. 12
(b) Explain the characteristics of laser light. 8
UNIT-III
6. (a) What is numerical aperture and acceptance angle ? Discuss in detail the various modes in fiberoptic. 15
(b) >X/light ray enters from air to fiber. Find the critical angle, acceptance angle and numerical aperture, tpiven, refractive index of air, core and cladding are 1,1.5 and 1.45 respectively, 5
7. (a) State and prove Gauss law in dielectrics. 10
-->
(b) Show that D =e0 E+'Pwhere the symbols have their usual meaning. 10
|
Attachment: |
| Earning: Approval pending. |
