Optionals IAS Mains Physics: Questions 167 - 171 of 306

Access detailed explanations (illustrated with images and videos) to 306 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 167

Edit

Appeared in Year: 2007

Describe in Detail

Essay▾

State the postulates of the special theory of relativity and based on these obtain Lorentz as well as inverse Lorentz transformations. Hence, obtain an expression to conclude that a moving clock runs more slowly than a stationary clock.

Explanation

  • The basic postulates on which the theory rests may be stated in – precise form thus:

(a) The laws of physics all take the same identical form for all frames of reference in uniform relation motion i. e. for all the inertial frames of reference. This is a direct consequence of the absence of an absolute or fixed frame of reference.

(b) The velocity of

… (879 more words) …

Question 168

Inertial and Non-Inertial Frames
Edit

Appeared in Year: 2016

Describe in Detail

Essay▾

Calculate the percentage contraction in the length of the rod in a frame of reference moving with velocity in a direction (1) parallel to its length and (2) at an angle of with its length. What is the orientation of the rod in the moving frame of reference in case.

Explanation

(1)

Let be the length of the rod, placed along the axis of, in a reference frame , at rest. Then, its length in a frame moving with velocity , relative to in a direction parallel to its length i. e. along the axis of is given by

Percentage contraction produced in the length of the rod

(2)

In this case, the component of the length of the rod along

… (110 more words) …

Question 169

Centre of Mass and Laboratory Coordinates
Edit

Appeared in Year: 2016

Describe in Detail

Essay▾

The distance between the centres of the carbon and oxygen atoms in the carbon monoxide gas molecule is. Locate the centre of mass of the molecule relative to the carbon atom.

Explanation

The centre of mass of the molecule will obviously lie on the line joining the and atoms. Let it be distance from the carbon atom. Then, since the atomic weights of carbon and oxygen are respectively and , we have

Hence the centre of mass of the molecule lies at a distance of from the centre of the carbon atom on the line joining the carbon and

… (2 more words) …

Question 170

Edit

Appeared in Year: 2010

Describe in Detail

Essay▾

Distinguish between classical and quantum theory of Paramagnetism. Explain the paramagnetism of free electrons on the basis of fermi Dirac distribution.

Explanation

The potential energy of magnetic dipole in a magnetic field is given by

The energy is least when the moment is parallel to the field, and thus moment lends to line up the field. The effect of temperature is to randomize the direction of the dipole. The result of these two competing processes is that some magnetization is produced. We can solve the p

… (1057 more words) …

Question 171

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

Appeared in Year: 2010

Describe in Detail

Essay▾

Distinguish between Einstein and Debye models of specific heats of solids. Obtain an expression for the specific heat of a solid on the basis of Debye model. Discuss the results for high and low temperature ranges.

Explanation

The salient features of the Einstein theory are listed below:

  1. A crystal consists of atom which may be regarded identical and independent harmonic oscillations.
  2. A solid consisting of N atoms is equivalent to 3N one-dimensional harmonic oscillations.
  3. All the oscillations vibrate with same natural frequency due to the identical environment of each.
  4. The os

… (932 more words) …