Advertisements
Advertisements
Question
When a ferromagnetic material goes through a hysteresis loop, its thermal energy is increased. Where does this energy come from?
Solution
When a ferromagnetic material is taken through the cycle of magnetisation, magnet dipoles of the material orient and reorient with time. This molecular motion within the material results in the production of heat, which increses thermal energy of material.
APPEARS IN
RELATED QUESTIONS
The property of diamagnetism is said to be present in all materials. Then, why are some materials paramagnetic or ferromagnetic?
Can we have magnetic hysteresis in paramagnetic or diamagnetic substances?
A paramagnetic material is placed in a magnetic field. Consider the following statements:-
(A) If the magnetic field is increased, the magnetisation is increased.
(B) If the temperature is increased, the magnetisation is increased.
A paramagnetic material is kept in a magnetic field. The field is increased till the magnetisation becomes constant. If the temperature is now decreased, the magnetisation ___________ .
A ferromagnetic material is placed in an external magnetic field. The magnetic domains ______________ .
The magnetic susceptibility is negative for _____________ .
The permanent magnetic moment of the atoms of a material is not zero. The material ________________ .
The permanent magnetic moment of the atoms of a material is zero. The material _________________ .
When a ferromagnetic material goes through a hysteresis loop, the magnetic susceptibility
(a) has a fixed value
(b) may be zero
(c) may be infinity
(d) may be negative
A rod is inserted as the core in the current-carrying solenoid of the previous problem. (a) What is the magnetic intensity H at the centre? (b) If the magnetization I of the core is found to be 0.12 A m−1, find the susceptibility of the material of the rod. (c) Is the material paramagnetic, diamagnetic or ferromagnetic?
Assertion: The earth¢s magnetic field is due to iron present in its core.
Reason: At a high temperature magnet losses its magnetism.
The time period of oscillation of a magnet in a vibration magnetometer is 1.5 sec. The time period of oscillation of another magnet similar in size, shape and mass but having 1/4 magnetic moment than that of the 1st magnet oscillating at the same place will be ______.
The primary origin of magnetism lies in ______.