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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
Distinguish between ‘paramagnetic’ and ‘ferromagnetic’ substances.
Which of the following substances is ductile?
A rod of magnetic material of cross-section 0.25 cm2 is placed in a magnetizing field of intensity 4000 A/m-1. The magnetic flux passing through the rod is 25 × 10-6 Wb. Find out
(a) relative permeability
(b) magnetic susceptibility and
(c) magnetisation of the rod.
The magnetic property of magnetic substance is associated with ____________.
Why does a paramagnetic sample display greater magnetisation (for the same magnetising field) when cooled?
Assertion: The ferromagnetic substance do not obey Curie’s law.
Reason: At Curie point a ferromagnetic substance start behaving as a paramagnetic substance.
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.
Which of the following has a permeability less than that of free space?
Magnetic susceptibility of a diamagnetic substance ______.
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:
