Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU)) B-Tech 1st Semester (First Semester) 2018-2019 Physics Question Paper
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B. Tech.
(SEM 1) THEORY EXAMINATION 2018-19
PHYSICS
Time: 3 Hours Total Marks: 100
Note: 1. Attempt all Sections. Ifrequ1re any missing data; then choose suitably.
SECTION A
l. Attempt all questions in brief. 2 1110 = 20
a. Write down the postulates of special theory of relativity. [C0 1]
b. How will you show that no particle can move with a velocity greater than the veloc1ty
of light in an inertial frame? [C0 1}
6. Why Maxwell proposed that Ampere?s law require modi?cation? [CO 2]
d. What do you mean by depth of penetration? [CO 2]
6. Determine the de-Broglie wavelength of a photon. [CO 3]
f. Discuss the physical signi?cance of a wave function. [CO 3]
g. Why two independent sources cannot be coherent?? _ = [C0 4]
h. What do you mean by resolving power of an optica}.;1 s'trument? [CO 4]
i. Distinguish between spontaneous and stimulated emissions. Which one is required for
laser? [C0 5]
j. What is the principle of operation of an optical fiber? [CO 5]? . e.
i SECTION B ? """
2. \ttempt any three parts Mthe following: . : 10 x 3: 30
a. Deduce the relativistic. velocity addition theorem. Show that it is consistent with
Einstein 5 second postulate ' [CO 1]
b. Write the Maxwell 5 equations in integral as well as in differential torm and explain
their physical signi?cance. Show that the velocity of plane electromagnetic wave in
the free space is given by c ? 1/\ (11080) [CO 2]
1'. Obtain time independent and time dependent Schio?inger 5 wave equations [C0 3]
d. Discuss the phenomenon of F raunhfofer diffraction at a single slit and show that the
relative intensities of the successive maximum are nearly [C 0 4]
4 _ 4 . 4
9H 25H 4911'
e. Discuss the structure of ankobtical ?ber. What are Various types of optical ?bers?
Explain their advantages and disadvantages. |CO 5]
SECTION C
3. Attempt any two parts of the following: 5 x 2 = 10
(a) What do you mean by length contraction? Deduce the necessary
expression for this.
(b) Obtain the volume of a cube, the proper length of each edge of
which is 10 when it is moving with velocity v along one edge of
A
[co 1]
[C01]
the cube
(c) Deduce an expression for the variation of mass with velocity. [CO I]
Attempt any two parts of the following: 5 x 2 = 10
(a) What is Poynting vector? Derive and explain Poynting theorem. [C O 2]
(b) Deduce Coulomb?s law of electro?statistics from Maxwell?s ?rst [CO 2]
equation.
(c) C alculate the magnitude of Poynting vector at the surface of the
sun. Given that power radiated by sun is 5.4 x 1028 watt and [CO 2]
radius ofsun is 7 x 10?1 m
Attempt any two parts of the following: 5 x 2 = 10
(a) A particle is in motion along a line it = 0 and x = L with zero
potential energy. At points for which x < 0 and x > L, the
potential energy is in?nite. Solving Schrodinger equation, obtain [CO 3]
energy eigen values & normalized wave function for the particle.
(b) What is Compton effect? Derive the necessary expression for [CO 3]
Compton shi?.
(c ) Show that V106,)", :J) = V(XJ?, Z)?'W is a wave function of [CO 3]
astationary state. , '
Attempt any two parts of the following: ,. 5 x 2 = 10
(2) Explain the formation of Newton?s nng Prove that in re?ected ,.
light the diameter 01 dark rings are proportional to the square {?054}! "
rootof natural numbers '
(by Light of wavelength 6000 A falls normally on a thin wedge-shaped
film of refracthe index 1 4f0rm1ng fringes that are 2 0 mm apart. Find [CO 4]
the angle of wedge m S??ohds
(c) 111 a grating spectrum which spectral line in 4Ill order will
overlap with 3?1" order line of 5461 A [L0 4]
Attempt any two parts of the following: , , 5 x 2 = 10
(3) Describe the construction and working of Rubv Laser with neat (?0 S
diagram [ " ? l
(b) Calculate the population ratio of two states in He-Ne laser that I(?0 5]
produces light of wavelength 6000A at 27?C
(c) Calculate the numerical apertuf???cceptance angle, and the
critical angle of the optical fiber "if the refractive index of the [CO 5]
core is 150 and refractive ipdex?ofcladding is 1.45.
This post was last modified on 29 January 2020