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
which of the following statements about earth's magnetism is correct
  • A
    The earth behaves as a magnet with the magnetic field pointing approximately from the geographic south-west to the north-east.
  • B
    The earth behaves as a magnet with the magnetic field pointing approximately from the geographic south to the north.
    Correct
  • C
    The earth behaves as a magnet with the magnetic field pointing approximately from the geographic south-east to the north-west.
  • D
    The earth behaves as a magnet with the magnetic field pointing approximately from the geographic east to the west.
2
which of the following statements about bar magnets is correct
  • A
    We can isolate the north, or south pole of a magnet
  • B
    north pole atrracts north pole
  • C
    We cannot isolate the north, or south pole of a magnet
    Correct
  • D
    south pole atrracts south pole
3
when iron filings are sprinkled on a sheet of glass placed over a short bar magnet
  • A
    The iron filings form a pattern of suggesting that the magnet has south pole similar to the negative charge
  • B
    The iron filings form a pattern of suggesting that the magnet has north pole similar to the positive charge
  • C
    The iron filings form a random pattern of suggesting that the magnet has random pole
  • D
    The iron filings form a pattern of suggesting that the magnet has two poles similar to the positive and negative charge of an electric dipole
    Correct
4
Which of the following statements about magnetic field lines true?
  • A
    The larger the number of field lines crossing per unit area, the weaker is the magnitude of the magnetic field B.
  • B
    The smaller the number of field lines crossing per unit area, the stronger is the magnitude of the magnetic field B.
  • C
    The magnetic field lines of a magnet (or a solenoid) form continuous closed loops
    Correct
  • D
    The perpendicular to the field line at a given point gives direction of magnetic field
5
In which case of comparing solenoid and bar magnet there is no exact similarity?
  • A
    moving a small compass needle in the neighbourhood of a solenoid enables tracing the flux lines
  • B
    There is a current entering and a current leaving a solenoid
    Correct
  • C
    flux lines enter one end of a solenoid
  • D
    soenoid can be broken into two weaker solenoids
6
Far axial magnetic field of a solenoid as well as bar magnet vary
  • A
    inversely as R squared R \( = \) axial distance to the magnet/solenoid
  • B
    directly as R squared R \( = \) axial distance to the magnet/solenoid
  • C
    inversely as R cubed R \( = \) axial distance to the magnet/solenoid
    Correct
  • D
    directly as R cubed R \( = \) axial distance to the magnet/solenoid
7
Compass needle of known magnetic moment m in a uniform magnetic field field experiences a torque equal to
  • A
    \(\vec{\tau}=\vec{m}.\vec{B}\)
  • B
    \(\vec{\tau}=\mu_0\vec{m}×\vec{B}\)
  • C
    \(\vec{\tau}=2\pi\vec{m}×\vec{B}\)
  • D
    \(\vec{\tau}=\vec{m}×\vec{B}\)
    Correct
8
magnetic potential energy \({{\rm{U}}_{\rm{m}}}\) of Compass needle of known magnetic moment m in a uniform magnetic field field is
  • A
    \(\vec{m}.\vec{B}\)
  • B
    \(-\vec{m}.\vec{B}\)
    Correct
  • C
    \(2\pi\vec{m}.\vec{B}\)
  • D
    \(2\vec{m}.\vec{B}\)
9
According to the dipole analogy \({\rm{1}}/{\varepsilon _0}\) corresponds to
  • A
    \({\rm{2}}{\mu _0}a\)
  • B
    \({\rm{1}}/{\mu _0}\)
  • C
    \(\pi {\mu _0}\)
  • D
    \({\mu _0}\)
    Correct
10
According to Gauss’s law for magnetism
  • A
    The net magnetic flux through any surface is zero.
    Correct
  • B
    The net magnetic flux through any closed surface is zero.
  • C
    The magnetic flux through any closed surface is zero.
  • D
    The magnetic flux through any surface is zero.
11
considering the magnetic field of the earth,the correct relation of the geographic pole and the magnetic poles is
  • A
    north magnetic pole is located near the south geographic pole but south magnetic pole is not located near the north geographic pole
  • B
    north magnetic pole is located near the south geographic pole and south magnetic pole is located near the north geographic pole
    Correct
  • C
    north magnetic pole is located near the north geographic pole
  • D
    north magnetic pole is not located near the south geographic pole but south magnetic pole is located near the north geographic pole
12
magnetic declination and dip refer to
  • A
    angle between latitude of magnetic axis and geographic axis,angle up or down with respect to horizontal of a magnetic needle
  • B
    angle between magnetic axis and geographic axis,angle up or down with respect to longitude of a magnetic needle
  • C
    angle between longitudinal magnetic axis and latitdinal geographic axis,angle up or down with respect to horizontal of a magnetic needle
  • D
    angle between magnetic axis and geographic axis,angle up or down with respect to horizontal of a magnetic needle
    Correct
13
If inclination is I,the horizontal component of the earth’s field is \({{\rm{H}}_{\rm{E}}}\) and \({{\rm{Z}}_{\rm{E}}}\) is the vertical component of the earth’s field, then tan(I) is
  • A
    \(\frac{Z_E^2}{H_E^2}\)
  • B
    \(\frac{H_E}{Z_E }\)
  • C
    \(\frac{Z_E}{H_E}\)
    Correct
  • D
    \(\frac{H_E^2}{Z_E^2 }\)
14
magnetic intensity is defined by
  • A
    \(\frac{\vec{B}}{\mu_0^2} - \vec{M}\)
  • B
    \(\frac{2\vec{B}}{\mu_0} - \vec{M}\)
  • C
    \(\frac{\vec{B}}{\mu_0^3} - \vec{M}\)
  • D
    \(\frac{\vec{B}}{\mu_0} - \vec{M}\)
    Correct
15
if \(\vec{H}\) =magnetic intensity,\(\chi\) =susceptibility, magnetic moment per unit volume \(\vec{M}\) equals
  • A
    \(\chi\vec{H}\)
    Correct
  • B
    \(\chi^2\vec{H}\)
  • C
    \(2\chi\vec{H}\)
  • D
    \(\pi\chi\vec{H}\)