Q.1
The periods of oscillation of two magnets in the same field in the ratio 2:If their moment of inertia are equal, ratio of their magnetic moments is
  • a) 1 : 2
  • b) 1 : 4
  • c)2 : 1
  • d)4 : 1
Q.2
When a magnet marked N - s is suspended in a horizontal position, so that it is free to rotate, the pole marked N shall point towards
  • a) south pole of earth's magnet
  • b) north pole of earth's magnet
  • c) geographic N pole
  • d) geographic S pole
Q.3
The relative permeability of iron is of the order of ...
  • a)1
  • b) 104
  • c)zero
  • d)10-4
Q.4
Curie's law state that
  • a) magnetic susceptibility is inversely proportional to the absolute temperature
  • b) magnetic susceptibility is inversely proportional the square root of the absolute temperature
  • c)magnetic susceptibility is directly proportional to the absolute temperature
  • d)magnetic susceptibility is independent of temperature
Q.5
The permanent magnetic moment of atoms or molecules of a diamagnetic material is
  • a) small
  • b) large
  • c)negative
  • d)zero
Q.6
The relation between magnetic susceptibility χm and relative permeability µr, is
  • a) χm=µr
  • b) χm - 1=µr
  • c) χm + 1=µr
  • d) χm=1- µr
Q.7
If M is magnetic moment developed in the material having volume V, then intensity of magnetization is given by the expression
  • a)MV
  • b) M / V
  • c)M √V
  • d)M / √V
Q.8
The relation between B, H and I in S.I. unit is
  • a) B=µo ( H + I)
  • b) B=H + 4π I
  • c)H=µo ( B + I)
  • d)none of these
Q.9
A temparary magnet is made of
  • a) cast iron
  • b) steel
  • c)soft iron
  • d)stainless steel
Q.10
Water is..
  • a) diamagnetic
  • b) paramagnetic
  • c) ferromagnetic
  • d) none of these
Q.11
The relative permeability of a medium is 0.What is its magnetic susceptibility?
  • a)0.925
  • b) -0.925
  • c)1.075
  • d)-1.075
Q.12
The moment of magnet ( 15cm ×2cm × 1cm) is 1.2 A-mWhat is its intensity of magnetization ?
  • a) 4 × 104 A/m
  • b) 2 × 104 A/m
  • c)104 A/m
  • d)none
Q.13
As magnetizing field on a ferromagnetic material is increased, its permeability..
  • a) increases
  • b) decreases
  • c)remains constant
  • d)can not say
Q.14
Magnetic field do not interact with
  • a) stationary charge
  • b) moving electric charges
  • c) stationary permanent magnet
  • d) moving permanent magnets
Q.15
Two identical thin bar magnets each of length l and pole strength m are placed at right angles to each other, with north pole of one touching south pole of the other , then the magnetic moment of the system is
  • a)ml
  • b) 2ml
  • c)√2 ml
  • d)ml/2
Q.16
The ratio of magnetic potentials due to magnetic dipole in the end position to that in broad side on position for the same distance from it is
  • a) zero
  • b) ∞
  • c)1
  • d)2
Q.17
A thin bar magnet of length 2l and breadth 2b pole strength p and magnetic moment M is divided into four equal parts with length and breadth of each part being half of original magnet. Then the pole strength of each part is
  • a) p
  • b) p/2
  • c)p/4
  • d)2p
Q.18
In above question, magnetic moment of each part is
  • a) M/4
  • b) M
  • c) M/2
  • d) 2M
Q.19
A circular loop is replaced by an equivalent magnetic dipole. then the equivalent magnetic dipole has a constant
  • a)pole strength m of each pole
  • b) length 2l of dipole
  • c)product of m and 2l
  • d)all of the above
Q.20
In a bar magnet, the magnetic field lines...
  • a) are not present
  • b) depend upon the cross-section area of the magnet
  • c)go from N-pole to s pole
  • d)go from S-pole to N-pole
Q.21
A magnetic needle hang using silk fiber oscillates in earth's magnetic field. If the temperature of this needle is raised beyond the curie temperature of the material of the needle, then [ CBSEB 2007]
  • a)the periodic time of the oscillation will increase
  • b) the periodic time of the oscillation will decrease
  • c)the periodic time of the oscillation will not change
  • d)the needle will stop oscillating
Q.22
Which of the following has negative magnetic susceptibility?
  • a) Ferromagnetic substance
  • b) Paramagnetic substance
  • c) Diamagnetic substance
  • d) None of above
Q.23
Which of the following has negative magnetic susceptibility
  • a)Ferromagnetic substance
  • b) Paramagnetic substance
  • c)Diamagnetic substance
  • d)None of the above
Q.24
Magnetization intensity for vacuum is ... [GSEB 2008]
  • a) negative
  • b) positive
  • c)∞
  • d)0
Q.25
A bar magnet with dipole moment m is kept perpendicular to a uniform magnetic field B. If it is released in this situation and it rotates and makes an angle θ with the magnetic field, then the work done in this process is ....
  • a)MB
  • b)MB cosθ
  • c)MBsinθ
  • d)MB(1-cosθ)
Q.26
The earth's magnetic field in a closed iron box is .... than the magnetic field outside the box
  • a) more
  • b) less
  • c) equal
  • d) zero
Q.27
A bar magnet has magnetic dipole moment M. Its initial position is parallel to a uniform magnetic field. In this position, the torque and force acting on its are .....
  • a)0,0
  • b) M × B and MB
  • c)M . B and MB
  • d)None of these
Q.28
If we place a bar magnet in the magnetic meridian with its north pole towards geographic north, the neutral point will be
  • a) on the axis of magnet
  • b) on the equatorial line of magnet
  • c)at 45° with axial line
  • d)at 45° with equatorial line
Q.29
A bar magnet is suspended with unspun thread. It lies in the magnetic meridian. the upper end of the thread is turned through 150°. It turns the magnet by 30° with the magnetic meridian. through what angle should the upper end of thread be turned to rotate the magnet through 90°
  • a)360°
  • b) 330°
  • c)300°
  • d)270°
Q.30
Which of the following does not represent the unit for magneticdipole moment?
  • a) Am2
  • b) T/J
  • c) J/T
  • d) Nm/T
0 h : 0 m : 1 s