Class 12 Magnetism And Matter CBSE Questions & Answers

Class 12 · Magnetism And Matter

This is Physics Class 12 Magnetism and Matter CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
A toroid wound with 60.0 turns/m of wire carries a current of 5.00 A. The torus is iron, which has a magnetic permeability of \({\mu _{\rm{m}}} = {\rm{ 5 }}000{\mu _0}\) under the given conditions. H and B inside the iron are
  • A
    340AT/m,1.88T
  • B
    340AT/m,2.88T
  • C
    300AT/m,1.88T
    Correct
  • D
    380AT/m,1.98T
2
Nitric oxide is a paramagnetic compound. The magnetic moment of each NO molecule has a maximum component in any direction of about one Bohr magneton.Interaction energy of such magnetic moments in a 1.5-T magnetic field is
  • A
    \({\rm{9}}.0{\rm{ }} \times {\rm{ 1}}{0^{ - {\rm{5}}}}{\rm{eV}}\)
  • B
    \({\rm{8}}.{\rm{9 }} \times {\rm{ 1}}{0^{ - {\rm{5}}}}{\rm{eV}}\)
  • C
    \({\rm{8}}.{\rm{7 }} \times {\rm{ 1}}{0^{ - {\rm{5}}}}{\rm{eV}}\)
    Correct
  • D
    \({\rm{8}}.{\rm{4 }} \times {\rm{ 1}}{0^{ - {\rm{5}}}}{\rm{eV}}\)
3
A cube-shaped permanent magnet is made of a ferromagnetic material with a magnetization M of about The side length is 2 cm. Magnetic dipole moment of the magnet is.
  • A
    \({\rm{5 A}}{{\rm{m}}^{\rm{2}}}\)
  • B
    \({\rm{3 A}}{{\rm{m}}^{\rm{2}}}\)
  • C
    \({\rm{4 A}}{{\rm{m}}^{\rm{2}}}\)
  • D
    \({\rm{6 A}}{{\rm{m}}^{\rm{2}}}\)
    Correct
4
A cube-shaped permanent magnet is made of a ferromagnetic material with a magnetization M of about The side length is 2 cm. Magnetic field due to the magnet at a point 10 cm from the magnet along its axis is
  • A
    0.003 T
  • B
    0.001 T
    Correct
  • C
    0.004 T
  • D
    0.002 T
5
permeability of a paramagnetic material is expected to decrease with increasing temperature because
  • A
    random thermal motion reduces magnetic moment alignment
    Correct
  • B
    random thermal motion increases magnetic moment alignment
  • C
    electrons go into forbidden gap
  • D
    electrons stop moving
6
If a magnet is suspended over a container of liquid air, it attracts droplets to its poles. The droplets contain only liquid oxygen and no nitrogen because
  • A
    oxygen is paramagnetic whereas nitrogen is diamagnetic
    Correct
  • B
    oxygen is ferrimagnetic whereas nitrogen is diamagnetic
  • C
    oxygen is diamagnetic whereas nitrogen is paramagnetic
  • D
    oxygen is ferromagnetic whereas nitrogen is diamagnetic
7
which of the following features of atomic structure determine whether an element is diamagnetic or paramagnetic
  • A
    number of electrons
  • B
    principal quantum number
  • C
    atomic weight
  • D
    orbital angular momentum ,spin angular momentum
    Correct
8
Correct unit of Bohr magneton is
  • A
    T
  • B
    J
  • C
    J/T
    Correct
  • D
    T/J
9
Diamagnetic susceptibilities are very nearly temperature independent because
  • A
    temperature does not knock off electrons
  • B
    principal quantum number is large
  • C
    There are no unpaired electrons in the same orbital
    Correct
  • D
    spin is only one way
10
An iron bar magnet of length 10cm and cross section 1 \({\rm{c}}{{\rm{m}}^{\rm{2}}}\) has a magnetization of \({\rm{1}}{0^{\rm{2}}}\). Magnet's pole strength is
  • A
    0.002 Am
  • B
    0.0015 Am
  • C
    0.0025 Am
  • D
    0.001 Am
    Correct
11
A cylinder of iron is placed so that it is free to rotate around its axis. Initially the cylinder is at rest, and a magnetic field is applied to the cylinder so that it is magnetized in a direction parallel to its axis. If the direction of the external field is suddenly reversed, the direction of magnetization will also reverse and the cylinder will begin rotating around its axis because
  • A
    Conservation of angular momentum and spin angular momentum is of the same nature as the angular momentum of rotating bodies
    Correct
  • B
    Conservation of parity
  • C
    Conservation of energy
  • D
    Conservation of mass
12
A short bar magnet placed with its axis at \({\rm{3}}0\) with a uniform external magnetic field of 0.25 T experiences a torque of magnitude equal to \({\rm{4}}.{\rm{5 }} \times {\rm{ 1}}{0^{ - {\rm{2}}}}\) J. What is the magnitude of magnetic moment of the magnet?
  • A
    0.36 J/T
    Correct
  • B
    0.26 J/T
  • C
    0.30 J/T
  • D
    0.33 J/T
13
A closely wound solenoid of 800 turns and area of cross section \({\rm{2}}.{\rm{5 }} \times {\rm{ 1}}{0^{-{\rm{4}}}}{{\rm{m}}^{\rm{2}}}\) carries a current of 3.0 A. What is its associated magneticm oment?
  • A
    0.8 J/T
  • B
    0.5 J/T
  • C
    0.6 J/T
    Correct
  • D
    0.4 J/T
14
A closely wound solenoid of 800 turns and area of cross section \({\rm{2}}.{\rm{5 }} \times {\rm{ 1}}{0^{-{\rm{4}}}}{{\rm{m}}^{\rm{2}}}\) carries a current of 3.0 A.It is free to turn about the vertical direction and a uniform horizontal magnetic field of 0.25 T is applied.Magnitude of torque on the solenoid when its axis makes an angle of \({\rm{3}}0^\circ \) with the direction of applied field
  • A
    0.070J
  • B
    0.080J
  • C
    0.075J
    Correct
  • D
    0.085J
15
A bar magnet of magnetic moment 1.5 J/T lies aligned with the direction of a uniform magnetic field of 0.22 T. What is the amount of work required by an external torque to turn the magnet so as to align its magnetic moment normal to the field direction?
  • A
    0.23J
  • B
    0.33J
    Correct
  • C
    0.43J
  • D
    0.38J