Test: Solid State Physics - 1 - Physics MCQ

The lattice constant of unit cell of BCC structure α - Iron is 0.288 nm. The number of atoms/mm² in the plane of (1 0 0) is_____x 10¹² atom/mm². (Answer should be an integer)

For a sphere of radius x, polarised along the radius vector such that  . The total charge is     (Answer should be integer).

The metals an oppaque to light for which

Optical excitation of intrinsic Germanium creates an average density of 10¹⁸ conduction electrons per m³ in the material at liquid nitrogen temperature. At this temperature electrons and holes mobilities are equal.
μ = 0.5 x 10⁴cm² /volts sec and Germanium dielectric constant is 20. The diffusion coefficient for electron is

In Raman effect

An ac current of frequency 1 GHz is observed through Josephson junction, the applied dc voltage is

The polarizability 'α' of an e^- moving in a circular orbit of radius ‘r’ about charge +e in a field directed at light angle to plane of orbit is

The density of states for electron hi a metal is given by D  (E)dE = 13.6x 10²⁷ E^1/2 dE and ρ = 8.5 x 10²⁸ /m³. The energy of Fermi level is___________eV. (Round off to three decimal places)

For lead the superconductivity occurs at 7.19 k when there is zero applied magnetic field. When the magnetic field 0.074 T is applied at temperature 2.0 k superconductivity will stop. The magnetic field that should be
applied so that superconductivity will not occur at any temperature is___________x 10^-3 T. (Answer should
be an integer).

The energy of the conduction band at which the probability of the conduction electrons state will occupied by
election is 90% at T = 800K. is__________(eV). [Given: E_F =5.52eV]
(Round off to two decimal places)

Calculate the relative permeability of material having magnetization of 3400 ampere/meter and flux density of 0.0045 wb/m².

A long thin uniformly magnetized needle of hard steel length 12 cm is suspended by a torsionless suspension and makes free, small angle oscillations about an axis through the center in a honzontal plane in the earth's magnetic field. The period of oscillation is four seconds. The density of magnetization of steel is

The energy of interaction of two atoms at a distane 'r' apait can be written as
 where, a, b are constants
If two atoms are pulled apart show that they will separete most easily when

Consider a crystal containing a paramagnetic impurity whose energy level are in a given magnetic field. The specific heat of the crystal at high temperature will vary with

A rough sketch of the absorbtion co-efficient for the EM radiation for a non magnetic pure solid substance. The solid absorb light in infrared (0.15 eV) and then does not absorb until the photon energy is 2.3 eV. The minimum number of atoms per unit cell in the crystal should be

X-rays are reflected from a simple cubic crystal by Bragg reflection. If the density of the crystal is measured with r.m.s. error of 3 parts in 10⁴ and if the angle made by the incident and reflected ray make with the crystal plane is 6° and is measured with an r.m.s. error 3.4 minutes of arc then what is the error in the determination of wavelength.

The basis vectors of a lattice is given by

The volume of the reciprocal lattice are given by