Solve your IGNOU Doubts

Question:

Prove that in a crystal undergoing deformation, the deformed crystal axes are not mutually perpendicular.

See Answer →

Question:

e) The wave function of a particle moving in the x-direction is given by:

$\Psi (x)=\left\{\begin{matrix} Nx(l-x) ,& 0<x<L\\0\,\,\,\,\,,elsewhere & \end{matrix}\right.$

Calculate the normalization constant.

See Answer →

Question:

The Debye temperatures of NaCl and KCl are 330 K and 220 K respectively. If the heat capacity of KCl at 5 K is $3.8\times10^{-2}J\,mol^{-1}K^{1}$ , calculate the heat capacity of NaCl at 15 K.

See Answer →

Question:

d) Calculate the commutator $\left [ p,e^{ik0x} \right ]$ where the function $e^{ik0x}$ may be expanded as: $e^{ik0x}=\sum _{n=0}^{\infty }\frac{(ik_0x)^n}{n!}$

See Answer →

Question:

The Young’s modulus of a linear mono-atomic chain of atoms of mass $10.6\times10^{-26}kg\,is\,2.0\times10^{11}Nm^{-2}.$ . If the inter-atomic separation is $2.8\,\AA$ , calculate the force constant K and the maximum frequency of the atoms.

See Answer →

Question:

c) A particle of mass m and zero energy has a wave function $\Psi (x)=N\,xe\frac{-x^2}{16},$ where N is a constant. Determine the potential energy $V(x)$ for the particle

See Answer →

Question:

The binding energy of CsCl is 150 kcal mol^-1 If the Madelung constant for CsCl is 1.763 and the repulsive exponent $n=10.6,$ calculate the equilibrium interatomic distance $r_e.$ (Take $\varepsilon_0=8.86\times10^{-12}$ Farad $m^{-1}$ .)

See Answer →

Question:

b) Calculate the deBroglie wavelength of a $^{87}Rb$ atom that has been laser cooled to $120\,\pi K.$ (Assume that the kinetic energy is $\frac{3}{2}k_BT).$

See Answer →

Question:

$\vec{a}_1=a \left ( \frac{\sqrt{3}}{2}\hat{i}+\frac{1}{2}\hat{j} \right );\vec{a}_2=a\left ( -\frac{\sqrt{3}}{2}\hat{i}+\frac{1}{2}\hat{j} \right )$ and $\vec{a}_3=c\hat{k}$

Obtain the volume of the primitive unit cell and the reciprocal lattice vectors.

See Answer →

Question:

a) Using Heisenberg’s uncertainty principle, estimate the energy and radius of the ground state of a hydrogen-like atom made of a proton and a muon. Assume that the

proton and the muon are bound by the Coulomb potentia $V(r)=\frac{e^2}{4\pi \varepsilon0r }.$ The mass of the muon is $106\,MeV/c^{2}.$

See Answer →

Question:

e) A star emits light with wavelength 120 nm. An observer on earth measures the wavelength of the light received from the star to be 600 nm. Calculate the speed with which the star is moving

See Answer →

Question:

d) Missiles are fired towards the earth from a spacecraft. The missiles are moving with a speed of 0.8c with respect to the spacecraft. If the spacecraft itself has a speed of 0.3c with respect to Earth, how fast are the missiles observed to travel with respect to Earth

See Answer →

Question:

c) The rest energy of a proton is 938 MeV. If its kinetic energy is also 938MeV, calculate its momentum and speed.

See Answer →

Question:

b) Supersonic jets are able to achieve maximum speeds of up to $3.0\times 10^{-1}c.$ Calculate the percentage contraction in the length of a jet plane travelling at this speed.

See Answer →

Question:

The direct lattice vectors for a lattice are given by:

See Answer →

Question:

A crystal of iridium is irradiated by x-rays with a wavelength of 0.721 Å. Calculate the angle of reflection from the (111) plane, given that the lattice constant of iridium is 3.84 Å.

See Answer →

Question:

Determine the boundaries of the first Brillouin zone of a bcc structure with a lattice constant 0.20 nm

See Answer →

Question:

Calculate the volume of the unit cell for fcc Pb given that its atomic radius is 0.175 nm.

See Answer →

Question:

In crystal growth why does the nucleation process become more stable as the size of the nucleus increases?

See Answer →

Question:

Distinguish between substitutional and interstitial impurities with the help of a diagram.

See Answer →

IGNOU Solved Assignments Assignments Ignou Projects Project Previous Year Solved Exam Papers Notes Notes Sample Question Papers Sample Question Papers

IGNOU NEWS

Assignment Submission Last Date Extended Till 30 June 2026 Click Here★★★IGNOU June 2026 TEE Date Sheet Released Click Here★★★

Ask Your Doubts