Download SGBAU (Sant Gadge Baba Amravati university) BSc 2019 Summer (Bachelor of Science) 4th Sem Physics Optics Laser n Renewable Energy Sources Previous Question Paper
B.Sc. (Part?II) Semester?IV Examination
4S?PHYSICS
(Optics, Laser and Renewable Energy Sources)
Time : Three Hours] [Maximum Marks : 80
NB. :? (1) ALL questions are compulsory.
1. (A)
(B)
(C)
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(2) Draw neat and labelled diagram wherever necessary.
Fill in the blanks :
(i) Propagation of light through a ?ber core depends on the phenomenon known as
(ii) The blue colour of the sky is due to the ................ of light.
(iii) The central spot of Newton?s ring by ret?lcctcd light is ..............
(iv) In Ruby laser ............. pumping is used. 2
Choose correct alternative :
(i) If N be the number of lines per cm. the grating element in cm will be ..............
2.54 , N.
(a) _N_ (b) 2.54
(c) N (d) 1?
N
(ii) In quantum optics. light is assumcd to consist of ..............
(a) Particle or photon (b) Wave
(c) Ray (d) Wave and ray
(iii) The 5.]. unit of power of radiation is ..............
(a) cal/m2 (b) jnulc
(c) w/m2 ((1) watts
(iv) A laser beam consists of ............
(a) Light material particles (b) Electrons
(c) Highly coherent photons (d) Cosmic rays 2
Answer in one sentence :
(i) What is ?ber Optics '3
(ii) What is half wave plate ?
(iii) De?ne dilTraction of light.
(iv) What is power of lens ? 4
(C ontd.)
?rJ
EITHER
(A) Obtain an exprcssion for path diffcrcncc in renamed ight from thin films. Hence also
obtain the conditions for bright and dark fringes. 6
(B) Explain the method to determine the wavelenglh 01? monochromatic light by using
Newton?s rings. 4
(C) Newton?s rings are observed in re?ected light 01' \xavc'lcngth 5.9A [0 5 cm. The diameter
of thc lO?? dark ring is 5 mm. Find the radiu> of curvature 0f the lens. 2
OR
(1?) What are focal points '? 2
(Q) Stale cardinal points. Explain nodal points emu prircipul points. 4
(R) Determine the equivalent focal length of mu thin co-uxial lens of focal length FI and
F2 separated by a distance 'u?. 6
EITHER
(A) Dcduce an expression for the resolving powe: ol' 1? plane transmission grating. 4
(B) Distinguish between 1?rcsnel and Fruunhol'er types of diil?raction. 3
(C ~) Explain resolving power of optical instrument unJ cxrlain Rayleigh?s criteria of resolution.
D
0R
(P) Explain the meaning of half period zones. Why are they so called ? 3
(Q) Give the clcmcnlar) theory of plane transmissaon grating. 6
(R) Light of wavelength 6250 A is? incident nounullv on .1 plane transmission grating.
A second order spectral line is obscn ed at an angle of 30?. Calculate the number of
lines pcr cm on the grating surface. 3
EITHER
(A) State and explain Brewster's law. 3
(B) What is quarlcr wave plate '.? Deducc the formula for its thickness. 4
(C) What are uniaxial and biax?iul cr} sluls ?L? (Jiw 01w example of each. 3
(D) What is hall?shadc polarimcter ?2 2
OR
(P) Give the theory 01" production of cllipticul .md circularly polarised light. 5
(Q) Explain the phenomenon of doublc ret'raclinn. 3
(R) Explain how Nicol Prism can bc uscd as u puluriscr. 4
EITHER
(A) Describe the construction and working of ruby laser. 5
(B) Explain the diiTcnencc bclwccn sponmnem..> 4nd stimulated CIIILSSiOIl. 3
(C) Stutc the medical and industrial applicevmws 01 laser. 4
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OR
9. (P) Explain how laser can be used for recording and reconstruction Of an image from
holograms. 6
(Q) Explain three level laser system. 4
(R?) What are the main characteristics of laser ? 3
EITHER
10. (A) De?ne:
(i) Acceptance angle
(ii) Critical angle. 2
(B) Derive an expression for numerical aperture. 4
(C) Describe ?ber optic communication system with block diagram. 6
0R
II. (P) I'prlain the phenomenon of total internal re?ection. 3
(Q) Give the advantages of optical ?ber over conventional communication system. 3
(R) Explain the types of optical ?ber. 6
EITHER
?12. (A) What is renewable energy ?.? 2
(B) Describe principle, construction and working of a solar cell. 6
(C) Describe solar water heater with natural circulation system. 4
OR
13. (P) What is fuel cell ? 2
(Q) Describe any two methods to store solar energy. 4
(R) Explain :
(i) Wind energy
(ii) Geothermal energy
(iii) Ocean energy. 6
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This post was last modified on 10 February 2020