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प्रश्न
Answer the following question.
Write three points of differences between para-, dia- and ferromagnetic materials, giving one example for each.
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उत्तर
Ferromagnetism:
These substances are strongly attracted by a magnetic field. Ferromagnetic substances can be permanently magnetized even in the absence of a magnetic field. These substances move (strongly) towards the strong field region when kept a non-uniform external magnetic field. Some examples of ferromagnetic substances are iron, cobalt, nickel, gadolinium
Paramagnetism:
The substances that are attracted by a magnetic field are called paramagnetic substances. These substances get magnetized in a magnetic field in the same direction but lose magnetism when the magnetic field is removed. Paramagnetic material moves (weakly) towards the weak field region when kept a non-uniform external magnetic field. To undergo paramagnetism, a substance must have one or more unpaired electrons.
Example O2
Diamagnetism:
This is a form of magnetism that is only exhibited by a substance in the presence of an externally applied magnetic field. It is generally quite a weak effect in most materials, although superconductors exhibit a strong effect. Diamagnetic material moves (very weakly) away from the strong-field region towards the weak field region. Diamagnetic atoms have only paired electrons. Example H2
संबंधित प्रश्न
The susceptibility of a magnetic material is − 2.6 × 10−5. Identify the type of magnetic material and state its two properties.
Draw magnetic field line when a (i) diamagnetic, (ii) paramagnetic substance is placed in an external magnetic field. Which magnetic property distinguishes this behaviour of the field line due to the substances?
Choose the correct option:
A rectangular magnet suspended freely has a period of oscillation equal to T. Now it is broken into two equal halves (each having half of the original length) and one piece is made to oscillate freely. Its period of oscillation is T′, the ratio of T′/T is ______.
Two identical bar magnets each of magnetic moment M, separated by some distance are kept perpendicular to each other. The magnetic induction at a point at the same distance d from the centre of magnets, is (µ0 = permeability of free space)
Why is diamagnetism, in contrast, almost independent of temperature?
A hydrogen atom is paramagnetic. A hydrogen molecule is
According to the Atomic theory, on heating a magnet, the thermal energy of the elementary magnet ______
A long solenoid has 1000 turns per metre and carries a current of 1 A. It has a soft iron core of µr = 1000. The core is heated beyond the Curie temperature, Tc.
- The H field in the solenoid is (nearly) unchanged but the B field decreases drastically.
- The H and B fields in the solenoid are nearly unchanged.
- The magnetisation in the core reverses direction.
- The magnetisation in the core diminishes by a factor of about 108.
Which substances are feebly magnetised in the direction of the magnetising field?
