Advertisements
Advertisements
Question
Magnetic field lines are always nearly normal to the surface of a ferromagnet at every point. (This fact is analogous to the static electric field lines being normal to the surface of a conductor at every point.) Why?
Advertisements
Solution
The permeability of a ferromagnetic material is always greater than one. Hence, magnetic field lines are always nearly normal to the surface of such materials at every point. The proof of this fact is based on the boundary conditions of the magnetic fields at the interface of two media.
RELATED QUESTIONS
A tangent galvanometer shows a deflection of 45° when 10 mA of current is passed through it. If the horizontal component of the earth's magnetic field is `B_H = 3.6 xx 10^-5 "T"` and radius of the coil is 10 cm, find the number of turns in the coil.
Answer in brief.
Discuss the Curie law for paramagnetic material.
The susceptibility of a paramagnetic material is χ at 27° C. At what temperature its susceptibility be χ/3?
The magnetic property of magnetic substance is associated with ____________.
Above the curie temperature the susceptibility of ferromagnetic substance varies ____________.
A small quantity of paramagnetic liquid is taken in a watch - glass and kept on two dissimilar magnetic poles. The liquid ____________.
A domain in a ferromagnetic substance is in the form of a cube of side length 1 µm. If it contains 6 x 1010 atoms and each atomic dipole has a dipole moment of 7 x 10-24 Am2, then magnetization of the domain is ____________.
A short bar magnet has a magnetic moment of 0.48 J T−1. Give the direction and magnitude of the magnetic field produced by the magnet at a distance of 10 cm from the centre of the magnet on
- the axis,
- the equatorial lines (normal bisector) of the magnet.
Why is diamagnetism, in contrast, almost independent of temperature?
Earth's magnetic field analyses has a horizontal component except at:-
Most of the substance show which of the magnetic property:-
According to the Atomic theory, on heating a magnet, the thermal energy of the elementary magnet ______
Essential difference between electrostatic shielding by a conducting shell and magnetostatic shielding is due to ______.
- electrostatic field lines can end on charges and conductors have free charges.
- lines of B can also end but conductors cannot end them.
- lines of B cannot end on any material and perfect shielding is not possible.
- shells of high permeability materials can be used to divert lines of B from the interior region.
A permanent magnet in the shape of a thin cylinder of length 10 cm has M = 106 A/m. Calculate the magnetisation current IM.
Magnetic susceptibility for a paramagnetic and diamagnetic materials is respectively ______.
Which of the following cannot modify an external magnetic field as shown in the figure?
The relative magnetic permeability of a substance X is slightly less than unity and that of substance Y is slightly more than unity, then ______.
Match List-I with List-II.
| List-I (Material) | List-II (Susceptibility) | ||
| A. | Diamagnetic | I. | χ = 0 |
| B. | Ferromagnetic | II. | 0 > χ ≥ −1 |
| C. | Paramagnetic | III. | χ >> 1 |
| D. | Non-magnetic | IV. | 0 < χ < ε |
Choose the correct answer from the options given below:
