Jawaharlal Nehru Technological University Kakinada 2012-1st Year B.Tech 1st st semester Engineering Physics R10 Set no:1 - Question Paper

Set Code No: R10103 / R10
No. 1
I B.Tech I Semester Regular/Supplementary exams January 2012
ENGINEERING PHYSICS - I (Common to all branches)
Time: three hours Max Marks: 75
ans any 5 ques. All ques. carry equal marks
1.(a) What is interference of light waves? elaborate the conditions necessary for obtaining
interference fringes?
(b) define Youngs double slit experiment and find an expression for fringe width.
(c) 2 narrow and parallel slits 0.08 cm apart are illuminated by light of frequency 8x 1011
kHz. It is desired to have a fringe width of 6x10 -4m. Where the screen should be placed from the slits?[5M + 6M + 4M]
2.(a) elaborate the differences ranging from interference and diffraction.
(b) define the Fraunhofer diffraction trend found with single slit.
(c) A plane transmission grating having 4250 lines per cm is illuminated with sodium light
normally. In 2nd order spectrum the spectral lines are deviated by 30o are observed. obtain the wavelength of the spectral line.[4M + 7M + 4M]
3.(a) elaborate the quarter and half wave plates?
(b) Derive the expressions for thickness of quarter and half wave plates.
(c) Plane polarized light passes through a quartz plate with its axis parallel to the face. compute the thickness of the plate so that the emergent light may be plane polarized. For quartz µ
e = 1.553, µo= 1.542 ? = 5.5x10-5 cm.[3M + 8M + 4M]
4.(a) describe crystal lattice, unit cell, lattice parameter and coordination number.
(b) define the FCC crystal structure and find the expression for its packing factor.
(c) Iron has BCC structure beneath 910 oC and is FCC structure above 910 oC. The atomic radius of an atom is the identical in both the cases. compute the ratio of the packing densities of bulk iron in the 2 structures at beneath 910 oC.
[4M + 7M + 4M]
5.(a) describe Miller indices for designating
(i) direction, (ii) plane, (iii) family of directions and (iv) family of planes.
(b) Sketch the ( one 0 2) and ( 0 1) planes in a cubic unit cell. (c) Derive an expression for inter planar distance ranging from parallel planes ( h k l ).[4M + 4M + 7M]
6.(a) elaborate the characteristics of a laser beam?
(b) define the construction and working of He-Ne laser.[5M + 10M]
7.(a) What is the principle behind the functioning of an optical fiber?
(b) explain different factors contributing to attenuation in optical fibers. (c) The optical power launched into an optical fiber is 1.5 mW. The fiber has attenuation of 0.5 db/km. If the power output is two µm, compute the fiber length.[3M + 8M + 4M]
8.(a) discuss various kinds of scans in NDT.
(b) discuss different applications of ultrasonic testing.
[8M + 7M]

Earning:   Approval pending.