Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Q. Define Fermi energy. Write down the expression for Fermi Dirac distribution law. Deduce an expression for Fermi energy of a system of free particles.
Sol. The Fermi Energy : it is important to determine how the electrons may distribute themselves in a band among the energies from zero to E. The number of energy levels in the energy rage dE available to a free particle enclosed in a box of volume V is given by each level can accommodate two electrons (one with spin up and one with spin down). Therefore if we refer to a unit volume, the total number of electrons per unit volume with energy between E and E + dE, is. The quality is shown in fig. for a given band the curve should stop at E. The number of electrons per unit volume that can be accommodated up to an energy E is given by
If the metal is in its ground state (which takes place at absolute zero), all electrons occupy the lowest probable energy levels in accordance with the exclusion principle. If the total number of electrons per unit volume is less than the total number of energy levels available in the band, the electrons will then occupy all energy states up to a maximum energy designated by E, and called the Fermi energy. If we put E = EF in equation (3), we must have n = n0. Therefore for the Fermi energy we obtain the value.
Thus the energy distribution of electrons in the metal, ground state corresponds to the shaded area in fig. when the Fermi energy is equal to the bandwidths the band is completely occupied. When a band is not completely filled, a small amount of energy is sufficient to excite the uppermost electrons to nearby energy levels.
Dalila decides to determine the coefficient of maximum static friction for wood against wood by conducting an experiment. First she places a block of wood on a small plank; nex
Question: A person is doing effort to locate the image of an object of a plane mirror by means of a ray-tracing diagram. The person draws a ray by the object which strikes the
Who are the best fiber optics manufacture? To single out a company would be grossly unfair since in such business the players are, usually, respected industrial corporations wi
A small spool and a large spool Using nails for axles fasten a large spool and a smaller spool to a block of wood. Slip a rubber band in excess of both spools. Turn the larger
Whatn is Fusion
what is michelson''s interferometer
: Construct a regular proof to derive the conclusion of the following argument: 1. (A & U) ~R 2. ~(~R v ~A) / ~U
Question 1. Discuss the physical characteristics of an X-ray beam. Write a note on factors influencing the quality and intensity of the X-ray beam 2. Explain the constructio
In a certain binary-star system, each star has the same mass which is 9.4 times of that of the Sun, and they revolve about their center of mass. The distance between them is the 3.
2 Kg of ice at -20 degree C is mixed with 5Kg of water 20 degree C in an insulating vessel having negligible heat capacity. Calculate the final mass of water remaining in the comta
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd