Q.1
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.2
Which of the following has negative magnetic susceptibility?
  • a) Ferromagnetic substance
  • b) Paramagnetic substance
  • c) Diamagnetic substance
  • d) None of above
Q.3
Which of the following has negative magnetic susceptibility
  • a)Ferromagnetic substance
  • b) Paramagnetic substance
  • c)Diamagnetic substance
  • d)None of the above
Q.4
Magnetization intensity for vacuum is ... [GSEB 2008]
  • a) negative
  • b) positive
  • c)∞
  • d)0
Q.5
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.6
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.7
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.8
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.9
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.10
Which of the following does not represent the unit for magneticdipole moment?
  • a) Am2
  • b) T/J
  • c) J/T
  • d) Nm/T
Q.11
The dimensional representation for magnetic flux density is .....
  • a)MLT-2
  • b) MLT-2A-1
  • c)MT-2A-1
  • d)MLT-2A-2
Q.12
Name the physical quantity which has the same dimension as √(K/MB) here K is moment of inertia
  • a) frequency
  • b) time
  • c)speed
  • d)distance
Q.13
When all the molecular dipoles in a magnet arrange themselves in the direction of magnetic field lines, the condition is called
  • a) permitivity
  • b) retentivity
  • c)coercivity
  • d)saturation
Q.14
Dimension of electric flux / magnetic flux are ...
  • a) L T-1
  • b) T-1 L-1
  • c) L3 T2A-2
  • d) MoLoTo
Q.15
Two magnetic dipoles of magnetic moment 1.0 Am2 each are placed at a separation of 2m with their axis perpendicular to each other. The resultant magnetic field at a point midway between dipoles is .....
  • a)√2 × 10⁻⁵
  • b) √5 × 10⁻⁵
  • c)2 × 10⁻⁵
  • d)3 × 10⁻⁵
Q.16
Name the instrument with which we measure the value of induced magnetic moment in a substance
  • a) galvanometer
  • b) magnetometer
  • c)tangent galvanometer
  • d)none of these instruments
Q.17
Magnetic field strength due to a short bar magnet on its axial line at a distance X is B. What is its value at the same distance on the equatorial line?
  • a) B/2
  • b) B
  • c)2B
  • d)4B
Q.18
Point P and Q are situated on the axis of 2cm long bar magnet at large distance d and 3d from its centre on opposite sides. The ratio of the magnetic field at P and Q will be approximately equal to .....
  • a) 3 : 1
  • b) 9 : 1
  • c) 27 : 1
  • d) 81 : 1
Q.19
A magnetic needle vibrates in the vertical plane perpendicular to the magnetic meridian. Its time period is 2 seconds. If the same needle vibrates in the horizontal plane and the time period is again 2 seconds, what is the angle of dip at the place?
  • a)30°
  • b) 45°
  • c)60°
  • d)None of these
Q.20
If the magnetic flux is represented in Weber, then the unit of magnetic induction will be ... [ GUJCET 2006]
  • b) Wb × m
  • d)Wb/m
  • a) Wb/m²
  • c)Wb × m²
Q.21
The length of a magnet is large compared to its width and breadth. The time period of its oscillation in a vibration magnetometer is 2s. The magnet is cut along its length into three equal parts and then three parts are placed on each other with their like poles together. The time period of this combination will be ...[ AIEEE 2004]
  • a) 2 s
  • b) (2/3) s
  • ac)2√3 s
  • d)2/√3 s
Q.22
Relative permitivity and permeability of material are εr and µr respectively. Which of the following values of these quantifies are allowed for diamagnetic material? [ AIEEE 2009]
  • a)εr=0.5 µr=0.5
  • b)εr=1.5 µr=1.5
  • c)εr=0.5 µr=1.5
  • d)εr=1.5 µr=0.5
Q.23
The dimension of magnetic field in M,L,T, and C ( coulomb) is given as .... [ AIEEE 2009]
  • a) MT-1C-1
  • b) MT-2C-1
  • c) MLT-1C-1
  • d) MT2C-2
Q.24
The magnetic moment has dimensions of .... [ AIIMS 2006]
  • a)LA
  • b) L2A
  • c)LT-1A
  • d)L2T-1A
Q.25
a coil having 100 turns and area of 0.001m2 is free to rotate about an axis, the coil is placed perpendicular to a magnetic field of 1.0 Wb/mIf the coil is rotated rapidly through an angle of 180°, how much charge will flow through the coil? The resistance of coil is 10Ω [ AFMC 2002]
  • a) 0.02 C
  • b) 0.04 C
  • c)0.08 C
  • d)0.01 C
Q.26
In which direction, would the magnetic field on the axis at a distance Z from the centre of the bar magnet be ( GUJCET 2009]
  • a) Its direction depends on the magnitude of magnetic moment (M) of the magnet
  • b) In the perpendicular direction of the magnetic moment (M) of the magnet
  • c) In the opposite direction of magnetic dipole moment (M) of the magnet
  • d) In the direction of magnetic dipole moment (M) of the magnet
Q.27
A bar magnet of length l and magnetic dipolemoment M is bent in the form of an arc as shown infigure. The new magnetic dipole moment will be…[ NEET 2013]
ch-17_que_no-289_img_no1.png
  • a) M
  • b) 3M/π
  • c) 2M/π
  • d) M/2
Q.28
Following figures show the arrangement of bar magnets in different configuration. Each magnet has dipole moment m. Which configuration has net magnetic dipole moment?
  • a)
    ch-17_qn-290choice_img_no1.png
  • b)
    ch-17_qn-290choice_img_no2.png
  • c)
    ch-17_qn-290choice_img_no3.png
  • d)
    ch-17_qn-290choice_img_no4.png
Q.29
A rectangular coil of length 0.12m and width 0.1mhaving 50 turns of wire is suspended vertically in auniform magnetic field of strength 0.2 Weber/mThe coil carries a current of 2 A. If the plane of thecoil is inclined at an angle of 30° with the directionof the field, the torque required to keep the coil instable equilibrium will be :
  • a) 0.12 Nm
  • b) 0.15 Nm
  • c) 0.20 Nm
  • d) 0.24 Nm
Q.30
A bar magnet is hung by a thin cotton thread in a uniform horizontal magnetic field and is in equilibrium state. The energy required to rotate it by 60° is W. Now the torque required to keep the magnet in this new position is …[NEET II-2016]
  • a) (√3 W)/2
  • b) 2W/√3
  • c) W/√3
  • d) √3 W
0 h : 0 m : 1 s