Applied Physics 1 - May 2014

First Year Engineering (Semester 1)

TOTAL MARKS: 60
TOTAL TIME: 2 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Use suitable data wherever required.
(4) Figures to the right indicate full marks.

Sove any five from the following :-

1 (a) What is x-rays? Why the x-ray are prefered to study crystaline solid.(3 marks) 1 (b) Represent the following in the cubic unit cell (021), (123), [121](3 marks) 1 (c) Find the miller indices of a set of parallel panes which makes intercepts in the ratio 3a:4b on the x and y axes and parallel ti Z-axis(3 marks) 1 (d) What is Fermi level and Fermi energy? Write Fermi-Dirac distribution function.(3 marks) 1 (e) Explain the concept of hole in a semiconductor (3 marks) 1 (f) Draw the structure of quartz crystal and explain its various axes.(3 marks) 1 (g) State and explain ohm's law in magnetic circuit?(3 marks) 2 (a) Describe the formation of energy band in solid? Explain how it helps to classify the solid in to conductors, insulator and semiconductor with proper diagram.(8 marks) 2 (b) Explain Dimond crystal structure with proper diagram and determine its APF?(7 marks) 3 (a) Derive the Bragg's law and describe the powder method to determine crystal structure of powdered specimen.(8 marks) 3 (b) The magnetic field strength of cooper is 10¹⁶ ampere / metre. And magnetic susceptibility is -0.8 x 10^-3. Calculate magnetic flux density ad magnetisation in cooper.(7 marks) 4 (a) What is liquid crystal state of matter? Draw the diagram to descibe molecular arrangement in their different phases?(5 marks) 4 (b) Mention different types of polarizability in a dielectric? Explain electorinc polarizability?(5 marks) 4 (c) Calculate electron and hole concentration in intrinsic silicon at room temperature if its electrical conductivity is 4 x 10^-4 mho/m. (mobility of electron = 0.14m²/v-s & mobility of hole =0.040 m²/v-s)(5 marks) 5 (a) Explain with neat diagram construction and working of solar cell.(5 marks) 5 (b) State the acoustic requirements of good auditorium. Explain how these requirements can be achieved.(5 marks) 5 (c) If the x-rays of wavelength 1.549 A^o will be reflected from crystal having spacing of 4.255 A^o, calculate the smallest glancing angle and highest order of reflection that can be observed.(5 marks) 6 (a) Explain with neat diagram Hysterisis effect in ferromagnetic material.(5 marks) 6 (b) Explain piezoelectric oscillator to produce USW?(5 marks) 6 (c) Explain the formation of barries potential in P-N Junction.(5 marks)