Discuss magnetic dipole moment. What is its effect on atom and on molecules? Explain. [5]
2.
An electron is placed midway between two fixed charges, $q_1 = 2.5*10^{-10} C$ and $q_2 = 5*10^{-10} C$. If the charges are 1 m apart, what is the velocity of the electron when it reaches a point 10 cm from $q_2$? [5]
Fundamentals of Solid State Physics
1.
Assuming that atoms in a crystal structure and arranged as close-packed spheres, what is the ratio of the volume of the atoms to the volume available for the simple cubic structure? Assume a one atom basis. [5]
Methods of Quantum Mechanics
1.
Explain Bloch theorem. Discuss its use in Kronig-Penney model and hence in band theory. [5]
2.
Describe Frank Hertz experiment. Discuss its result and outline limitations. [10]
3.
A small particle of mass $10^{-6} gm$ moves along the x axis; its speed is uncertain by $10^5 m/sec$. (a) what is the uncertainty in the x coordinate of the particle? (b) Repeat the calculation for an electron assuming that the uncertainty in its velocity is also $10^5 m/sec$. use the known values for electrons and Planck's constant. [5]
4.
What is the probability of finding a particle in a well of width $a$ at a position $\frac{a}{4}$ from the wall if $n = 1$, if $n = 2$, if $n = 3$. Use the normalized wavefunction $\psi(x) = \left(\frac{2}{a}\right)^{1/2} \sin\left(\frac{n\pi x}{a}\right) e^{-\frac{iEt}{\hbar}}$ [5]
Rotational Dynamics and Oscillatory Motion
1.
Set up differential equation for an oscillation of a spring using Hooke's and Newton's second law. Find the general solution of this equation and hence the expressions for period, velocity and acceleration of oscillation. [10]
2.
A large wheel of radius 0.4 m and moment of inertia 1.2 $kgm^2$, pivoted at the center, is free to rotate without friction. A rope is wound around it and a 2-kg weight is attached to the rope. When the weight has descended 1.5 m from its starting position (a) what is downward velocity? (b) what is the rotational velocity of the wheel? [5]
Semiconductor and Semiconductor devices
1.
Explain the process of semiconductor purification by describing the terms Zone refining, single crystal growth, and scheme of IC production. Give an account of electronic component fabrication on a chip. [10]
2.
Explain the construction and working of bipolar junction transistor (BJT). [5]
Universal Gates and Physics of Integrated Circuits
1.
The output of a digital circuit $(y)$ is given by this expression:$y = (CB + \overline{C}A)(\overline{B}A)$ where $A$, $B$ and $C$ represent inputs. Draw a circuit of the above equation using OR, AND and NOT gate and hence find its truth table. [5]