# Magnetism and Matter MCQ Class 12 Physics

Please refer to Chapter 5 Magnetism and Matter MCQ Class 12 Physics with answers below. These multiple-choice questions have been prepared based on the latest NCERT book for Class 12 Physics. Students should refer to MCQ Questions for Class 12 Physics with Answers to score more marks in Grade 12 Physics exams. Students should read the chapter Magnetism and Matter and then attempt the following objective questions.

## MCQ Questions Class 12 Physics Chapter 5 Magnetism and Matter

The Magnetism and Matter MCQ Class 12 Physics provided below covers all important topics given in this chapter. These MCQs will help you to properly prepare for exams.

Question. The strength of the earth’s magnetic field is
(a) constant everywhere.
(b) zero everywhere.
(c) having very high value.
(d) vary from place to place on the earths surface.

D

Question. Tangent law is applicable only when:
(a) two uniform and mutually perpendicular magnetic fields exist
(b) two magnetic fields exist
(c) horizontal component of earth’s magnetic field is present
(d) uniform magnetic field are used

A

Question. The angle of dip at a certain place where the horizontal and vertical components of the earth’s magnetic field are equal is
(a) 30°
(b) 75°
(c) 60°
(d) 45°

D

Question. The magnetic moment of a magnet is 0.1 amp × m2. It is suspended in a magnetic field of intensity 3 × 10–4 weber/m2. The couple acting upon it when deflected by 30º from the magnetic field is
(a) 1 × 10–5 N m
(b) 1.5 × 10–5 N m
(c) 2 × 10–5 N m
(d) 2.5 × 10–5 N m

B

Question. When 2 ampere current is passed through a tangent galvanometer, it gives a deflection of 30º. For 60º deflection, the current must be
(a) 1 amp.
(b) 2 3 amp.
(c) 4 amp.
(d) 6 amp.

D

Question. Which of the following has higher magnetic susceptibility?
(a) diamagnetic
(b) paramagnetic
(c) ferromagnetic
(d) None of these

C

Question. The primary origin of magnetism lies in
(a) atomic current and intrinsic spin of electrons.
(b) polar and non polar nature of molecules.
(c) pauli exclusion principle.
(d) electronegative nature of materials.

A

Question. The magnetic lines of force inside a bar magnet:
(a) do not exist
(b) depends on area of cross-section of bar magnet
(c) are from N-pole to S-pole of the magnet
(d) are from S-pole to N-pole of the magnet.

D

Question. S.I. unit of flux is :
(a) Ohm
(b) Weber
(c) Tesla
(d) None

B

Question. In a moving coil galvanometer, we use a radial magnetic field so that the galvanometer scale is :
(a) exponential
(b) linear
(c) algebraic
(d) logarithmic

B

Question. The variation of magnetic susceptibility (x) with temperature for a diamagnetic substance is best represented by

B

Question. At a temperatur of 30°C, the susceptibility of a ferromagnetic material is found to be ∫ . Its susceptibility at 333°C is
(a) ∫
(b) 0.5 ∫
(c) 2∫
(d) 11.1∫

B

Question. A current carrying power line carries current from west to east. What will be direction of magnetic field 1 meter above it?
(a) N to S
(b) S to N
(c) E to W
(d) W to E

A

Question. The magnetic field of earth is due to:
(a) induction effect of the sun
(b) the presence of a large magnet at the centre of the earth
(c) interaction of cosmic rays with the current of earth
(d) motion and distribution of some material in an outside the earth

D

Question. The Mariner’s compass is provided with Gimbals arrangement so as to :
(a) keep the needle always horizontal
(b) give a direct reading of declination
(c) give the direct value of dip
(d) all of the above

C

Question. What is the value of angle of dip at the magnetic equator?
(a) 0o
(b) 90o
(c) 45o
(d) Nearly 30o

A

Question. What is the net magnetic moment of an atom of a diamagnetic material?
(a) Greater than 1
(b) Less than 1 but greater than zero
(c) Less than zero but greater than ‒1
(d) Zero

D

Question. Which among the following is denoted by δ?
(a) Horizontal component
(b) Magnetic meridian
(c) Magnetic declination
(d) Magnetic inclination

D

Question. A thin bar magnet of length 2 l and breadth 2 b pole strength m 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) m
(b) m/2
(c) 2 m
(d) m/4

B

Question. In the above question, magnetic moment of each part is
(a) M/4
(b) M
(c) M/2
(d) 2 M

A

Question. Which of the following is a natural magnet?
(a) Magnetic needle
(b) Bar magnet
(c) Magnetite
(d) Horseshoe magnet

C

Question. Which of the following has a low value in ferrites?
(a) Conductivity
(b) Permeability
(c) Magnetic susceptibility
(d) All the above

A

Question. Identity the unlike pair
(a) ‘Hard magnet’ is associated with ‘alnico’
(b) ‘Soft magnet’ is associated with ‘ soft iron’
(c) ‘ Bar magnet ‘ is associated with ‘ Equivalent solenoid ‘
(d) ‘ Electromagnet is associated with ‘ loud speaker ‘

D

Question. The primary origin(s) of magnetism lies in
(a) Pauli exclusion principle.
(b) polar nature of molecules.
(c) intrinsic spin of electron.
(d) None of these.

B

Question. Two short magnets have equal pole strengths but one is twice as long as the other. The shorter magnet is placed 20 cms in tan A position from the compass needle. The longer magnet must be placed on the other side of the magnetometer for no deflection at a distance equal to
(a) 20 cms
(b) 20 (2)1/3 cms
(c) 20 (2)2/3 cms
(d) 20 (2)3/3 cms

B

Question. A dip needle lies initially in the magnetic meridian when it shows an angle of dip q at a place. The dip circle is rotated through an angle x in the horizontal plane and then it shows an angle of dip θ’.

A

Question. Ferrites may be:
(a) ant. ferromagnetic
(b) ferromagnetic
(c) ferrimagnetic
(d) None of the above

B

Question. Lines of force, due to earth’s horizontal magnetic field, are
(a) elliptical
(b) curved lines
(c) concentric circles
(d) parallel and straight

D

Question. A long solenoid having a magnetic moment ‘M’ which corresponds to bar magnet is
(a) Magnetic dipole moment will be Equal for both bar magnet and solenoid
(b) More magnetic moment for solenoid
(c) More magnetic moment for bar magnet
(d) None of these

A

Question. At a certain place, horizontal component is √3 times the vertical component. The angle of dip at this place is
(a) 0
(b) π/3
(c) π/6
(d) None of these

C

Question. A freely suspended magnet oscillates with period T in earth’s horizontal magnetic field. When a bar magnet is brought near it, such that the magnetic field created by bar magnet is in same direction as earth’s horizontal magnetic field, the period decreases to T/2 . The ratio of the field of the magnet F to the earth’s magnetic field (H) is
(a) 1 : 3
(b) 1 : 1
(c) 3 : 1
(d) 9 : 1

C

Question. Curie temperature is the temperature above which
(a) a ferromagnetic material becomes paramagnetic.
(b) a ferromagnetic material becomes diamagnetic.
(c) a paramagnetic material becomes diamagnetic.
(d) a paramagnetic material becomes ferromagnetic.

A

Question. Pick out the origin of magnetic field
(a) Intrinsic spin of electrons and electric Current
(b) Polarity of molecules
(c) Pauli’s exclusion principle
(d) Electronegativity of materials

A

Question. how to given sentences with us and have them maximum magnetic susceptibility ?
(a) Calcium
(b) Chromium
(c) Oxygen
(d) Tungsten

B

Question. Example for ferri-magnetic materials
(a) salts of transition elements
(b) rare earth elements
(c) transition metals
(d) Ferrites

D

Question. A vibration magnetometer placed in magnetic meridian has a small bar magnet. The magnet executes oscillations with a time period of 2 sec in earth’s horizontal magnetic field of 24 microtesla. When a horizontal field of 18 microtesla is produced opposite to the earth’s field by placing a current carrying wire, the new time period of magnet will be
(a) 1 s
(b) 2 s
(c) 3 s
(d) 4 s

D

Question. A short bar magnet of magnetic moment 0.4J T–1 is placed in a uniform magnetic field of 0.16 T. The magnet is in stable equilibrium when the potential energy is
(a) – 0.064 J
(b) zero
(c) – 0.082 J
(d) 0.064 J

A

Question. Which of the following is imprecise statement about the relative magnetic permeability
(a) Relative magnetic permeability of a material is dimensionless .
(b) Relative magnetic permeability for vacuum medium is one .
(c) Relative magnetic permeability for ferromagnetic material is always greater than 1 to large extent.
(d) Relative magnetic permeability for paramagnetic material is greater than one

D

Question. Basic source of magnetism ______________.
(a) Charged particles alone
(b) Movement of charged particles
(c) Magnetic dipoles
(d) Magnetic domains

B

Question. The net magnetic moment of two identical magnets each of magnetic moment M0, inclined at 60° with each other is

C

Question. A magnetic needle vibrates in a vertical plane parallel to the magnetic meridian about a horizontal axis passing through its centre. Its frequency is n. If the plane of oscillation is turned about a vertical axis by 90°C, the frequency of its oscillation in vertical plane will be
(a) n
(b) zero
(c) less than n
(d) more than n

C

Question. Magnetic permeability has units as
(a) Tesla
(b) Henry
(c) Tesla / m
(d) Henry / m

D

Question. If a toroid uses bismuth for its core, the field in the core compared to that in empty core will be slightly
(a) greater
(b) smaller
(c) equal
(d) None of these

B

Question. The relative permeability of a medium is 0.075. What is its magnetic susceptibility?
(a) 0.925
(b) – 0.925
(c) 1.075
(d) –1.075

B

Question. The radius of curvature of the path of charged particle in a uniform magnetic file is directly proportional to the
(a) charge on fie particle
(b) Momentum of particle
(c) energy of particle
(d) Strength of field

B

Question. The Mariner’s compass is provided with Gimbals arrangement so as to :
(a) keep the needle always horizontal
(b) give a direct reading of declination
(c) give the direct value of dip
(d) all of the above

C

Question. The time period of oscillation of a magnet in a vibration magnetometer is 1.5 sec. The time period of oscillation of another magnet similar in size, shape and mass but having 1/4 magnetic moment than that of the 1st magnet oscillating at the same place will be
(a) 0.75 sec
(b) 1.5 sec
(c) 3.0 sec
(d) 6.0 sec

C

Question. Two identical magnetic dipoles of magnetic moments 1.0 A-m2 each, placed at a separation of 2 m with their axis perpendicular to each other. The resultant magnetic field at point midway between the dipole is
(a) 5 × 10–7 T
(b) √5 × 10–7 T
(c) 10–7 T
(d) 2 × 10–7 T

B

Question. Two isolated point poles of strength 30 A-m and 60 A-m are placed at a distance of 0.3m. The force of repulsion is
(a) 2 × 10–3 N
(b) 2 × 10–4 N
(c) 2 × 105 N
(d) 2 × 10–5 N

A

Question. Time periods of vibation of two bar magnets in sum and difference positions are 4 sec and 6 sec respectively. The ratio of their magnetic moments M1 / M2 is
(a) 6 : 4
(b) 30 : 16
(c) 2 . 6 : 1
(d) 1 . 5 : 1