EASY
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What is the relation between susceptibility and temperature?

Important Questions on Matter and Magnetism

MEDIUM
A domain in ferromagnetic iron in the form of cube is having 5×105 atoms. If the side length of this domain is 1.5 μm and each atom has a dipole moment of 8×10-24 A m2, then magnetisation of domain is 
MEDIUM
A bar magnet is demagnetized by inserting it inside a solenoid of length 0.2 m, 100 turns, and carrying a current of 5.2 A. The coercivity of the bar magnet is:
MEDIUM
Hysteresis loops for two magnetic materials A  and B are given below:
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These materials are used to make magnets for electric generators, transformer core and electromagnet core. Then it is proper to use:
EASY

The B-H curve for a ferromagnet is shown in the figure. The ferromagnet is placed inside a long solenoid with 1000 turns cm-1. The current that should be passed in the solenoid to demagnetize the ferromagnet completely is, 
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EASY
The magnetization of bar magnet of length 5 cm, cross-sectional area 2 cm2 and net magnetic moment 1 A m2 is
HARD
Nickel (Z=28) combines with a uninegative monodentate ligand to form a diamagnetic complex NiL 4 2 . The hybridisation involved and the number of unpaired electrons present in the complex are respectively:
EASY
Which one of the following characteristics is not associated with a paramagnetic material?
MEDIUM
The coercivity of a small magnet, where the ferromagnet gets demagnetised is 3×103 A/m. The current required to be passed in a solenoid of length 10 cm and number of turns 100, so that the magnet gets demagnetised when inside the solenoid is
MEDIUM

Consider the regular array of vertical identical current-carrying wires (with the direction of current flow as indicated in the figure below) protruding through a horizontal table. If we scatter some diamagnetic particles on the table, they are likely to accumulate-

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EASY
If Mz= magnetization of a paramagnetic sample, B= external magnetic field, T= absolute temperature, C= curie constant then according to Curie's law in magnetism, the correct relation is
MEDIUM
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The figure gives experimentally measured B vs. H variation in a ferromagnetic material. The retentivity, coercivity and saturation, respectively, of the material are:
EASY
A paramagnetic material has 1028 atoms m-3. Its magnetic susceptibility at temperature 350 K is 2.8×10-4. Its susceptibility at 300 K is
EASY
Coercivity of a magnet where the ferromagnet gets completely demagnetized is 3×103Am-1. The minimum current required to be passed in a solenoid having 1000 turns per metre, so that the magnet gets completely demagnetized when placed inside the solenoid is
EASY

A perfectly diamagnetic sphere has a small spherical cavity at its centre, which is filled with a paramagnetic substance. The whole system is placed in a uniform magnetic field B. Then the field inside the paramagnetic substance is:

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EASY

Magnetic materials used for making permanent magnets P and magnets in a transformer T have different properties of the following, which property best matches for the type of magnet required?

EASY
An example of a perfect diamagnet is a superconductor. This implies that when a superconductor is put in a magnetic field of intensity B, the magnetic field Bs inside the superconductor will be such that
EASY
A 25 cm long solenoid has the radius 2 cm and 500 turns. It carries a current of 15 A. If it is equivalent to a magnet of the same size and magnetization M Magnetic momentvolume,then  M is:
EASY
Magnetic susceptibility for a paramagnetic and diamagnetic material is respectively