PTU B.Tech Electrical 1st Year Paper 2012 Physics Punjab Technical University Exam 2012 1st Year Physics Test September and March Question Paper Free Download Punjab Technical University Physics Question Papers 2012 PTU B.Tech Electrical 1st Year Question Paper 2012 for all students Previous Year old Past Papers of PTU B.Tech Electrical 1st Year Paper 2012 Physics Punjab Technical University September 2012 and March 2012 Exam B.Tech Electrical 1st Year Sample Model Question Papers Free Download PDF
(a) What are the main parts of a laser system? What do you understand by optical pumping? Explain different pumping schemes.
(b) Calculate the energy and momentum of a photon of a laser beam having
wavelength of 6000 A
(a) Discuss step index and graded index optical fibres.
(b) What are the factors that affect light propagation in optical fibers.
Section – C
fMarks: 8 Each)
(a) Establish Einstein’s mass-energy relationship. Mention some important physical phenomenon which are explained by this relation.
(b) What is the work required to be done to increase the velocity of an electron from 0.4c to O.8c?
(a) Explain the origin of X-ray spectra and explain why the absorption spectra is continuous with edges.
(b) Calculate the velocity of the electron beam which produces X-rays of
(a) What is Compton effect? Derive an expression for the increase in wavel ength of X-rays scattered from a free stationary electron.
(b) An electron is moving in a 1- dimensional box of width I A .Calculate its minimum energy.
What is Meissner effect? Prove that Meissner effect and zero resistance are independent attributes of a superconductor.
(b) Explain briefly BCS theory of superconductors.
PTU B.Tech Electrical 1st Year Paper 2012 Physics