Explore topic-wise MCQs in Physics.

This section includes 17 Mcqs, each offering curated multiple-choice questions to sharpen your Physics knowledge and support exam preparation. Choose a topic below to get started.

1.

The variation of the intensity of magnetisation (I) with respect to the magnetising field (H) in a diamagnetic substance is described by the graph      [KCET 2002]

A. OD
B. OC
C.   \[ML{{T}^{-1}}\] and \[ML{{T}^{0}}\]  
D. OA
Answer» C.   \[ML{{T}^{-1}}\] and \[ML{{T}^{0}}\]  
2.

A current carrying coil is placed with its axis perpendicular to N-S direction. Let horizontal component of earth's magnetic field be Ho and magnetic field inside the loop is H. If a magnet is suspended inside the loop, it makes angle \[\theta \] with H. Then \[\theta \]=     [Orissa PMT 2004]

A. \[{{\tan }^{-1}}\left( \frac{{{H}_{0}}}{H} \right)\] 
B. \[{{\tan }^{-1}}\left( \frac{H}{{{H}_{0}}} \right)\]
C.   Angular momentum
D. \[{{\cot }^{-1}}\left( \frac{{{H}_{0}}}{H} \right)\]
Answer» B. \[{{\tan }^{-1}}\left( \frac{H}{{{H}_{0}}} \right)\]
3.

The angle of dip at a certain place is 30o. If the horizontal component of the earth?s magnetic field is H, the intensity of the total magnetic field is     [UPSEAT 1993, 2000; MP PMT 2002]

A. \[\frac{H}{2}\]   
B. \[\frac{2H}{\sqrt{3}}\]
C.   \[M{{L}^{-1}}{{T}^{-1}}\]   
D. \[H\sqrt{3}\]
Answer» C.   \[M{{L}^{-1}}{{T}^{-1}}\]   
4.

Due to the earth's magnetic field, charged cosmic ray particles [CBSE PMT 1997]

A. Require greater kinetic energy to reach the equator than the poles
B. Require less kinetic energy to reach the equator than the poles
C.   \[{{A}^{-2}}{{T}^{-4}}M{{L}^{3}}\] 
D. Can never reach the poles
Answer» D. Can never reach the poles
5.

A dip needle in a plane perpendicular to magnetic meridian will remain [NCERT 1975; MP PMT 1984; MP PET 1995]

A. Vertical
B. Horizontal
C.   Momentum and impulse
D. At an angle of dip to the horizontal
Answer» B. Horizontal
6.

At the magnetic north pole of the earth, the value of horizontal component of earth's magnetic field and angle of dip are, respectively [MP PMT 1994]

A. Zero, maximum
B. Maximum, minimum
C.   \[M{{L}^{0}}{{T}^{-1}}\]
D. Minimum, minimum
Answer» B. Maximum, minimum
7.

A line passing through places having zero value of magnetic dip is called  [CPMT 1987]

A. Isoclinic line  
B. Agonic line
C.   \[{{v}_{T}}\propto \eta rmg\]
D. Aclinic line
Answer» E.
8.

The line on the earth's surface joining the points where the field is horizontal is    [MNR 1985; UPSEAT 1999; Pb PET 2004]

A. Magnetic meridian
B. Magnetic axis
C.   Momentum 
D. Magnetic equator
E. (e) Isogonic line
Answer» E. (e) Isogonic line
9.

The angle of dip at a place is 40.6o and the intensity of the vertical component of the earth's magnetic field \[V=6\times {{10}^{-5}}\]Tesla. The total intensity of the earth's magnetic field (I) at this place is [MP PMT 1993]

A. \[7\times {{10}^{-5}}tesla\]   
B. \[6\times {{10}^{-5}}tesla\]
C.    \[\frac{m}{6\pi \eta rv}\]   
D. \[9.2\times {{10}^{-5}}tesla\]
Answer» E.
10.

The unit for molar susceptibility is

A. m3
B. kg-m?3 
C.    \[x=\frac{1}{2},\,y=-\frac{1}{2}\]
D. No units
Answer» B. kg-m?3 
11.

An iron rod of volume \[{{10}^{-4}}{{m}^{3}}\] and relative permeability 1000 is placed inside a long solenoid wound with 5 turns/cm. If a current of 0.5 A is passed through the solenoid, then the magnetic moment of the rod is

A. \[10\,\,A{{m}^{2}}\]   
B. \[15\,\,A{{m}^{2}}\]
C.   Rate of change of momentum 
D. \[25\,\,A{{m}^{2}}\]
Answer» E.
12.

Two short magnets of equal dipole moments M are fastened perpendicularly at their centre (figure). The magnitude of the magnetic field at a distance d from the centre on the bisector of the right angle is

A. \[\frac{{{\mu }_{0}}}{4\pi }\frac{M}{{{d}^{3}}}\]
B. \[\frac{{{\mu }_{0}}}{4\pi }\frac{M\sqrt{2}}{{{d}^{3}}}\]
C.   Weight of a standard kilogram mass
D.  \[\frac{{{\mu }_{0}}}{4\pi }\frac{2M}{{{d}^{3}}}\]
Answer» D.  \[\frac{{{\mu }_{0}}}{4\pi }\frac{2M}{{{d}^{3}}}\]
13.

Assertion   :   For making permanent magnets, steel is preferred over soft iron. Reason     : As retentivity of steel is smaller.

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.   Angular momentum and Planck's constant
D. If the assertion and reason both are false.
E. If assertion is false but reason is true.
Answer» C.   Angular momentum and Planck's constant
14.

Assertion   :   The susceptibility of diamagnetic materials does not depend upon temperature. Reason     : Every atom of a diamagnetic material is not a complete magnet in itself.

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.   \[ML{{T}^{-2}}\]  
D. If the assertion and reason both are false.
E. If assertion is false but reason is true.
Answer» D. If the assertion and reason both are false.
15.

Assertion   :   When a magnet is brought near iron nails, only translatory force act on it. Reason     : The field due to a magnet is generally uniform.

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.   Power of a convex lens 
D. If the assertion and reason both are false.
E. If assertion is false but reason is true.
Answer» E. If assertion is false but reason is true.
16.

Assertion   :   Magnetism is relativistic. Reason     : When we move along with the charge so that there is no motion relative to us, we find no magnetic field associated with the charge.

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.   \[{{M}^{0}}L{{T}^{-1}}\]
D. If the assertion and reason both are false.
E. If assertion is false but reason is true.
Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
17.

Assertion   :   We cannot think of magnetic field configuration with three poles. Reason     : A bar magnet does exert a torque on itself due to its own field.    [AIIMS 2002]

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.   \[M{{L}^{2}}{{T}^{2}}{{A}^{-1}}\]  
D. If the assertion and reason both are false.
E. If assertion is false but reason is true.
Answer» E. If assertion is false but reason is true.