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Class 12 Physics MCQ Questions of Magnetism and Matter with Answers?

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Students who can Practice MCQ Questions for Class 12 with Answers to improve your score more marks in Board Exams. These Class 12 Physics MCQ Questions of Magnetism and matter with answers have been prepared as per the latest syllabus, and examination pattern suggested in class 12 by CBSE. Here, you’ll also get links to access some very valuable articles for the preparation of the upcoming CBSE Board Exam.

Students of CBSE Class 12 having Physics together of their subjects can check some important Class 12 Physics MCQ Questions of Magnetism and Matter with Answers.  MCQ Questions for class 12 Physics for important part of exams for Class 12 Physics and if practiced properly can help you to get higher marks in exams.

Practice MCQ Question for Class 12 Physics chapter-wise 

1. S.I. unit of flux is :

(a) Ohm
(b) Weber
(c) Tesla
(d) None

2. Which of the following has a low value in ferrites?

(a) Conductivity
(b) Permeability
(c) Magnetic susceptibility
(d) All the above

3. Ferrites may be:

(a) ant. ferromagnetic
(b) ferromagnetic
(c) ferrimagnetic
(d) None of the above

4. 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

5. A magnetic dipole moment is a vector quantity directed from:

(a) S to N
(b) N to S
(c) E to W
(d) W to E

6. 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

7. The magnetic field of the earth can be modelled by that of a point dipole placed at the centre of the earth. The dipole axis makes an angle of 11.3° with the axis of the earth. At Mumbai, declination is nearly zero. Then,

(a) the declination varies between 11.3 W to 11.3E
(b) the least declination is 0
(c) the plane defined by dipole axis and the earth axis passes through Greenwich
(d) declination averaged over the earth must be always negative

8. Magnetic lines of force due to a bar magnet do not intersect because

(a) a point always has a single net magnetic field
(b) the lines have similar charges and so repel each other
(c) the lines always diverge from a single force
(d) the lines need magnetic lenses to be made to interest

9. Assertion : A paramagnetic sample display greater magnetisation (for the same magnetic field) when cooled.

Reason : The magnetisation does not depend on temperature

(a) Assertion is correct, reason is correct; reason is a correct explanation for assertion.
(b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(c) Assertion is correct, reason is incorrect
(d) Assertion is incorrect, reason is correct

10. The magnetic susceptibility is negative for

(a) diamagnetic material only
(b) paramagnetic material only
(c) ferromagnetic material only
(d) paramagnetic and ferromagnetic materials

11. Assertion : Electromagnetic are made of soft iron.

Reason : Coercivity of soft iron is small.

(a) Assertion is correct, reason is correct; reason is a correct explanation for assertion.
(b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(c) Assertion is correct, reason is incorrect
(d) Assertion is incorrect, reason is correct

12. The primary origin (s) of magnetism lies in

(a) atomic currents
(b) polar nature of molecules
(c) extrinsic spin of electron
(d) None of these

13. Demagnetisation of magnets can be done by

(a) rough handling
(b) heating
(c) magnetizing in the opposite direction
(d) All of the above

14. A bar magnet is cut into two equal halves by a plane parallel to the magnetic axis. Of the following physical quantities the one which remains unchanged is

(a) pole strength
(b) magnetic moment
(c) intensity of magnetisation
(d) None of these

15. When a current in a circular loop is equivalently replaced by a magnetic dipole

(a) the pole strength m of each pole is fixed
(b) the distance d between the poles is fixed
(c) the product md is fixed
(d) None of these

16. A circular loop carrying a current is replaced by an equivalent magnetic dipole. A point on the axis of the loop is in

(a) end-on position
(b) broadside-on position
(c) both
(d) None of these

17. A diamagnetic material in a magnetic field moves

(a) perpendicular to the field
(b) from stronger to the weaker parts of the field
(c) from weaker to the stronger parts of the field
(d) None of these

18. The magnetic moment of a bar magnet is thus ...A... to the magnetic moment of an equivalent solenoid that produces the same magnetic field. Here, A refers to

(a) unequal
(b) different
(c) equal
(d) same

19. The lines of force due to earth’s horizontal magnetic field are

(a) parallel and straight
(b) concentric circles
(c) elliptical
(d) curved lines

20. At the magnetic north pole of the earth, the value of the horizontal component of earth’s magnetic field and angle of dip are respectively

(a) zero, maximum
(b) maximum, minimum
(c) maximum, maximum
(d) minimum, minimum

21. Which of the following is responsible for the earth’s magnetic field?

(a) Convective currents in earth’s core
(b) Diversive current in earth’s core
(c) Rotational motion of earth
(d) Translational motion of earth

22. One can define ...A... of a place as the vertical plane which passes through the imaginary line joining the magnetic North and the South–poles. Here, A refers to

(a) geographic meridian
(b) magnetic meridian
(c) magnetic declination
(d) magnetic inclination

23. Metals getting magnetised by orientation of atomic magnetic moments in external magnetic field are called

(a) diamagnetic
(b) paramagnetic
(c) ferromagnetic
(d) antimagnetic

24. The materials suitable for making electromagnets should have

(a) high retentivity and low coercivity
(b) low retentivity and low coercivity
(c) high retentivity and high coercivity
(d) low permeability and high retentivity.

25. The given figure represents a material which is

(a) paramagnetic
(b) diamagnetic
(c) ferromagnetic
(d) none of these

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Answer :

1. Answer :  (b) Weber

Explanation: The CGS unit is the Maxwell and SI unit of magnetic flux is the Weber (Wb).

2. Answer : (a) Conductivity

Explanation: Conductivity is the ability of any material to flow electric current through it. Ferrites have a low conductivity but still some electric current can go through it.

3. Answer : (c) ferrimagnetic

Explanation: They are ferrimagnetic, meaning they can be magnetized or attracted to a magnet. Unlike other ferromagnetic materials, most ferrites are not electrically conductive, making them useful in applications like magnetic cores for transformers to suppress eddy currents.

4. Answer : (d) are from S-pole to N-pole of the magnet

Explanation: The magnetic lines of force inside a bar magnet are from south pole to north pole of the magnet.

5. Answer : (a) S to N

Explanation: Magnetic dipole moment of a bar magnet is a vector and it's direction is from South Pole to North Pole.

6. Answer : (b) linear

Explanation: In a moving cell galvanometer, we use a radial magnetic field so that the galvanometer scale is linear.

7. Answer : (a) the declination varies between 11.3 W to 11.3E

Explanation: Since the axis of the magnetic dipole placed at the centre of earth makes an angle 11.3∘ with the axis of earth, two possibilities arises as shown in figure. Hence the declination varies between 11.3W to 11.3E.

8. Answer : (a) a point always has a single net magnetic field

Explanation: Magnetic lines of force due to a bar magnet do not intersect Each Other because there is only a single. It has a single net magnetic field.

9. Answer : (c) Assertion is correct, reason is incorrect

Explanation: A paramagnetic sample displays greater magnetisation when cooled, this is because at lower temperature, the tendency to disrupt the alignment of dipoles (due to magnetising field) decreases on account of reduced random thermal motion.

10. Answer : (a) diamagnetic material only

Explanation: The magnetic susceptibility indicates whether a material is repelled out or attracted of a magnetic field. It is negative only for diamagnetic  material. It is positive for paramagnetic material and ferromagnetic material has large positive  magnetic susceptibility.

11. Answer : (b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

Explanation: Electromagnets are magnets, which can be turned on and off by switching the current on and off. As the material in electromagnets is subjected to cyclic changes (magnification and demangetisation), the hysteresis loss of the material must be small. The material should attain high value of I and B with low value of magnetising field intensity H. As soft iron has small coercivity, so it is a best choice for this purpose.

12. Answer : (a) atomic currents

Explanation: Atomic currents and intrinsic spins of electrons are responsible for origin of magnetism.

13. Answer : (d) All of the above

Explanation: Demagnetization processes include heating past the Curie point, applying a strong magnetic field, applying alternating current, or hammering the metal. Demagnetization occurs naturally over time. The speed of the process depends on the material, the temperature, and other factors.

14. Answer : (c) intensity of magnetisation

Explanation: For each half pole strength m becomes half

M = m × 2l becomes half and volume V = a × 2l also becomes half therefore, magnetic intensity remains constant.

15. Answer : (c) the product md is fixed

Explanation: Magnetic moment is the product of pole strength and the distance between the poles. If the loop is replaced by an equivalent magnetic dipole, the product md is fixed.

16. Answer : (a) end-on position

Explanation: Any point on the axis of the dipole is called end on position.

17. Answer : (b) from stronger to the weaker parts of the field

Explanation: A diamagnetic material in a magnetic field moves from stronger to the weaker part of the field.

18. Answer : (c) equal

Explanation: Since a bar magnet and a corresponding solenoid produce similar magnetic fields. Hence the magnetic moment of a bar magnet is equal to the magnetic moment of an equivalent solenoid that produces the same magnetic field.

19. Answer : (d) curved lines

Explanation: The lines of force due to earth's horizontal magnetic field are curved lines. The earth's magnetic field is produced as if It had a short bar magnet inside it, with its south pole in the northern hemisphere.

20. Answer : (a) zero, maximum

Explanation: At magnetic north pole of earth, H = 0 and \(\delta\) =90, maximum.

21. Answer : (a) Convective currents in earth’s core

Explanation: The earth's core is hot and molten. Hence, convective current in earth’s core is responsible for it’s magnetic field.

22. Answer : (b) magnetic meridian

Explanation: The vertical plane which passes through the magnetic axis of a freely suspended magnet at rest is called magnetic meridian. The magnetic meridian is an equivalent imaginary line connecting the magnetic south and north pole and can be taken as the magnetic force lines along the surface of the earth.

23. Answer : (b) paramagnetic

Explanation: In paramagnetic metals, magnetism is acquired by orientation of atomic magnetic  dipoles.

24. Answer : (b) low retentivity and low coercivity

Explanation: The retentivity of an electromagnet should be low so that after removing the electric current to the substance doesn't get magnetized and return to its original state. Hence, the materials suitable for making electromagnets should have low retentivity and low coercivity.

25. Answer : (b) diamagnetic

Explanation: In the given figure, since magnetic field line move away from the substance, it represent a paramagentic substance.

Click here to practice  MCQ Question for Magnetism and Matter Class 12

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