Home 
About
Blog
Discuss electrical conductivity of semiconductors. Derive expression for conductivity in terms of impurity ionization energy. Give a plot to dicuss 'Theoretical temperature dependence of the electrical conductivity of an impurity semiconductor'.
Describe processes involved in the fabrication of integrateds circuits include epitaxial growth, oxidation, oxide removal and pattern definition, doping (impurities in the Si), and interconnection of omponents.
Find expression for force on a current-carrying wire in a magnetic field to find the force experienced by a single charge.
Attempt any Eight questions
[8x5=40]Give spectrum of Hydrogen atom and discuss its lines.
Give a brief account of Krongi-Penny model.
Descrive th term 'space quantization'.
A given spring stretches 104 m when a force of 20N pulls on it. A 2-kg block attached to it on a frictionless surface is pulled to the right 0.2 m and released.
(a) What is frequency of oscillation of the block?
(b) What are the velocity and acceleration when x = 0.12m, on the block's first passing this point?
A proton is moving with a velocity v = (3 × 105i + 7 × 105k)m/sec in a region wher there is a magnetic field B = 0.4 j T. Find the force experienced by the proton.
In neutron spectroscopy a beam of mono-energetic neutrons is obtained by reflecting reactor neutrons from a beryllium crystal. If the separation between the atomic planes of the beryllium crystal is 0.732 Å, what is the angle between the incident neutron beam and the atomic planes that will yield a monochromatic beam of neutrons of wavelength 0.1 A?
(a) How many atomic states are there in hydrogen with n=3?
(b) How are they distributed among the sub shells? Label each state with the appropriate set of quantum numbers n, l, ml, ms.
(c) Show that the number of states in a shell, that is, states having the same n, is given by 2n2. (Hint: 1+2+3+.......+n=n(n+1)/2).
The density of aluminum is 2.70 g/cm3 and its molecular weight is 26.98 g/mole.
(a) Calculate the Fermi energy.
(b) If the experimental value of EF is 12 eV, what is the electron effective mass in alu-minum? [Aluminum is trivalent].
Analyze the circuit shown in the figure below. Determine the logic function performed by the circuit by making and justifying the appropriate truth table.