B.E-B.E 2nd Sem Applied Science-II(University of Pune, Pune-2013)

UNIVERSITY OF PUNE
[4361]-9
F. E. (Common)
Applied Science-II
Physics
(2008 Pattern)
Total No. of Questions : 6 [Total No. of Printed Pages :2]

Time : 3 Hours                                                                                                  Max. Marks : 80

Instructions :

(1) Neat diagram must be drawn wherever necessary.

(2) Black figures to the right indicate full marks.

(3) Your advised to attempt not more than 03 questions.

(4) Use of logarithmic tables, slide rule, Mollier charts, electronic pocket calculator and steam
tables is allowed.
(5) Assume suitable data, if necessary.

Constants :

Velocity of light (c) = 3 × 108 m/sec.

Mass of electron (m) = 9.1 × 10-31 kg

Charge on electron (e) = 1.6 × 10-19 C

Planck’s constant (h) = 6.625 × 10-34J-S

Q1. a) Explain how the wave group is formed, and obtain an expression for a group
velocity. [7]
b) Explain in short, why ψ is not directly related with probability and obtain
Schrodinger’s time dependent wave equation [6]
c) Obtain Heisenberg’s uncertainty principle in terms of energy and time [4]
OR
Q2.
a) Derive an expression for the energy levels and wave functions of a particle
enclosed within infinite deep potential well. Draw the probability
distribution curves. [7]
b) State Heisenberg’s uncertainty principle and establish it with the help of
single slit diffraction experiment [6]
c) For the particle moving with non-relativistic energy, show that the group
velocity is equal to the particle velocity. [4]
Q3.
a) State the properties of Laser and explain construction and working of solid
state laser. [7]
b) Explain following properties of superconductors.
1) Critical magnetic field [3]
2) Critical current density. [3]
c) State the advantages of optical fiber communication technology over the
conventional methods [4]
OR
Q4.
a) What is holography? State its principle. Explain the process of holography
recording and reconstruction [7]
b) Explain the Meissner effect. Show that superconductors are perfect
diamagnet. [6]
c) Explain with the help of energy level diagram [4]
1) Spontaneous emission &
2) Stimulated emission.
Q5.
a) What is Hall effect? Obtain an expression for Hall voltage and Hall
coefficient. State applications of Hall effect. [6]
b) Explain any two properties nanoparticles. [6]
c) Calculate the conductivity of pure silicon at room temperature when the
concentration of carriers is 1.5 × 1016/m3 and the mobilities of electrons
and holes are 0.12 and 0.05 m2/v-sec respectively at room temperature. [4]
OR
Q6.
a) Explain principle, construction and working of solar cell. Explain its
characteristic curve [6]
b) Explain with neat labeled diagram the synthesis of metal nanoparticles by
colloidal route. [6]
c) A silver wire is in the form of a ribbon 0.50cm wide and 0.10 mm thick.
When a current of 2Amp passes through the ribbon perpendicular to a 0.80

Tesla magnetic field, how large a hall voltage is produced along the width?
The density of silver is 10.5 gm/cm3.
(At.wt of silver = 108) [4