BE Civil Engineering Semester 1 (FE First Year)University of Mumbai
Share
Notifications

View all notifications
Books Shortlist
Your shortlist is empty

Define the critical temperature. Slow that in the superconducting state the material is perfectly diamagnetic. - BE Civil Engineering Semester 1 (FE First Year) - Applied Physics 1

Login
Create free account


      Forgot password?

Question

Define the critical temperature. Slow that in the superconducting state the material is perfectly diamagnetic. 

Solution

The critical temperature is the transition temperature at which the normal state of a conductor changes to superconducting state.
A superconducting material kept in a magnetic field expels the magnetic flux out its body when cooled below the critical temperature and exhibits perfect diamagnetism. This is called MEISSNER EFFECT.

⦁ It is found that as the temperature of the specimen is lowered to Tc, the magnetic flux is suddenly and completely expelled from it. The flux expulsion continues for T < Tc. The
effect is reversible. 

⦁ When the temperature is raised from below Tc . The flux density penetrates the specimen again at T = Tc and the material turns to the normal state.
⦁ For the normal state the magnetic induction inside the specimen is given by:

B = μo (H+M) = μO(1+χ) H………………………………………..(1)

Here H is the applied magnetic field , m is the magnetization produced within the specimen , is χ the susceptibility of the material and μ is the permeability of free space.

At T<Tc as seen above

B = 0 

Hence  equation (1) reduced to,

M = -H

And thus χ = `M/H `=-1

⦁ The specimen is therefore a perfect diamagnetic. The diamagnetism produces strong repulsion to the external magnets.
⦁ This effect is used to identify a superconductor , in levitation effect and suspension effect.

 

 

  Is there an error in this question or solution?

APPEARS IN

Solution Define the critical temperature. Slow that in the superconducting state the material is perfectly diamagnetic. Concept: Meissner Effect.
S
View in app×