Optionals IAS Mains Physics: Questions 145 - 149 of 307

Access detailed explanations (illustrated with images and videos) to 307 questions. Access all new questions- tracking exam pattern and syllabus. View the complete topic-wise distribution of questions. Unlimited Access, Unlimited Time, on Unlimited Devices!

View Sample Explanation or View Features.

Rs. 750.00 -OR-

How to register? Already Subscribed?

Question 145

Euler's Equation of Motion of a Rigid Body

Appeared in Year: 2016

Describe in Detail

Essay▾

A horizontal pipe of non – uniform bore has water flowing through it such that the velocity of flow is at a point where the pressure is of mercury column. What is the pressure at a point where the velocity of flow is ? Take and density of water .

Explanation

Here of mercury column , , d

In accordance with Bernoulli՚s equation,

Where is the pressure at the second point.

Or

So that

Or

Whence,

of mercury column.

… (2 more words) …

Question 146

Appeared in Year: 2016

Describe in Detail

Essay▾

What is Raman Effect? Describe briefly the characteristics of pure rotational spectra. The small rotational Raman displacement for molecule is . Find the internuclear distance between the atoms forming the molecule.

Explanation

  • When a strong beam of visible or ultra violet line – spectra light illuminates a gas, a liquid or a transparent crystal, a small fraction of light is scattered in all directions. The spectrum of the scattered light is found to consist of lines the same frequencies as that of the incident beam (Rayleigh lines) , and also certain weak lines of change…

… (284 more words) …

Question 147

Appeared in Year: 2016

Describe in Detail

Essay▾

Given a proton for which measured in the laboratory. What are the corresponding relativistic energy and momentum? Take .

Explanation

or .

The rest mass of proton is

Hence its mass at velocity is given by

Hence its relativistic energy

Now as we know

Relativistic energy of the proton

To determine the momentum of the electron, we use the relation,

Whence

And

Substituting the value of , we have

Thus, the momentum of the proton .

Question 148

Elementary Ideas About High Temperature Superconductivity
Edit

Appeared in Year: 2016

Describe in Detail

Essay▾

With the help of a Schematic diagram, show how entropy and specific heat vary with temperature for a superconductor.

Explanation

  • In all superconductors, the entropy decrease markedly on cooling below the critical temperature . Measurements for aluminum are plotted in Fig (1) . The decrease in entropy between the normal state and the superconducting state tells us that the superconducting state is more ordered than the normal state, for the entropy is a measure of the disorde…

… (319 more words) …

Question 149

Dulong-Petit, Einstein, and Debye's Theories of Specific Heat of Solids

Appeared in Year: 2016

Describe in Detail

Essay▾

Explain the principle of (I) induced absorption (II) spontaneous emission and (II) stimulated emission. Show the ratio of Einstein՚s coefficients is given by .

Explanation

  • An atomic system is characterized by discrete energy states, and usually the atoms occupy the lowest energy state, known as the ground state. An atom in a lower energy state may be excited to a higher energy state through a number of processes, one process being absorption of electromagnetic radiation of proper frequency. On the other hand, an atom…

… (666 more words) …