# Magnetism and Matter MCQ | Class 12 | Physics | Chapter-5

## Magnetism and Matter MCQ Chapter 5

Below are some of the very important NCERT Magnetism and Matter MCQ Class 12 Physics Chapter 5 with answers. These Magnetism and Matter MCQ have been prepared by expert teachers and subject experts based on the latest syllabus and pattern of CBSE Term 1 examination.

We have given these Magnetism and Matter MCQ Class 12 Physics questions with answers to help students understand the concept.

MCQ Questions for Class 12 Physics are very important for the latest CBSE Term 1 and Term 2 pattern. These MCQs are very important for students who want to score high in CBSE Board, NEET and JEE exam.

We have put together these NCERT Magnetism and Matter MCQ for Class 12 Physics Chapter 5 with answers for the practice on a regular basis to score high in exams. Refer to these MCQs questions with answers here along with a detailed explanation.

## MCQ

1 . If a hole is made at the centre of a bar magnet, then its magnetic moment

1. does not change
2. decreases
3. increases
4. vanishes

2. On cutting a solenoid in half, the field lines remain _______, emerging from one face of the solenoid and entering into the other face.

1. alternate
2. discontinuous
3. continuous
4. irregular

3. North pole of a magnet is brought near a stationary negatively charged conductor. Will the pole experience any force?

1. Yes
2. No
3. Depends on the magnitude of pole strength
4. Can’t say

4. The magnetic moment of a bar magnet is thus _________ to the magnetic moment of an equivalent solenoid that produces the same magnetic field.

1. same
2. different
3. unequal
4. equal

5. The incorrect statement regarding the lines of force of the magnetic field B is

1. magnetic lines of force for a closed curve
2. due to magnet the magnetic force of the magnetic lines of force never cut each other
3. magnetic intensity is a measure of lines of force passing through a unit area held normal to it
4. inside a magnet its magnetic lines of force move from north pole of the magnet towards the south pole

6. The magnetic dipole moment of a solenoid having N turns is given as

1. NIA
2. NIA2
3. NI2A
4. NI2A2

7. In the case of bar magnet, lines of magnetic induction

1. run continuously through the bar and outside
2. emerge in circular path from the middle of the bar
3. are produced only at the north pole like rays of light from a bulb
4. start from the north pole and end at the south pole

8. The magnetic induction B and the force F on a pole m are related by

1. F = mB
2. F = m / B
3. B = mF
4. F = B / m

9. A north pole of strength 50 Am and south pole of strength 100 Am are separated by a distance of 10 cm in air. Find the force between them.

1. 20 x 10-6 N
2. 25 x 10-3 N
3. 30 x 10-18 N
4. 50 x 10-3 N

10. The strength of the Earth’s magnetic field is

1. zero everywhere
2. constant everywhere
3. vary from place to place on the earth surface
4. having very high value

11. Horizontal component of the Earth’s magnetic field remains is zero at

1. magnetic poles
2. equator
3. an altitude of 60°
4. a latitude of 60°

12. Which of the following is responsible for the Earth’s magnetic field?

1. rotational motion of earth
2. translational motion of earth
3. convective currents in Earth’s core
4. diversify currents in Earth’s core

13. The vertical component of Earth’s magnetic field is zero at

1. magnetic equator
2. magnetic poles
3. geographical poles
4. north pole

14. At neutral point, the horizontal component of the magnetic field due to magnet is

1. in the opposite direction of the earth’s horizontal magnetic field
2. equal to earth horizontal magnetic field
3. in the same direction of the earth horizontal magnetic field
4. both 1 and 2

15. A dip circle is placed in a plane perpendicular to the magnetic meridian. The opponent angle of dip is

1. 0°
2. 45°
3. 60°
4. 90°

Click Below To Learn Chemistry Term-1 Syllabus Chapters MCQs

16. At a certain place, the horizontal component of Earth’s magnetic field is √3 times the vertical component. The angle of dip at that place is

1. 30°
2. 45°
3. 60°
4. 90°

17. The horizontal component of the Earth’s magnetic field is 3.6 x 10-5 T where the dip angle is 60°. The magnitude of Earth’s magnetic field is

1. 2.1 x 10-4 T
2. 7.2 x 10-5 T
3. 2.8 x 10-4 T
4. 3.6 x 10-5 T

18. The Earth’s magnetic field at some place on magnetic equator of earth is 0.5 x 10-4 T. Consider the radius of earth at that place as 6400 km. Then, the magnetic dipole moment of the Earth in Am2 is

1. 1.05 x 1023
2. 1.15 x 1023
3. 1.31 x 1023
4. 1.62 x 1023

19. At a certain place, horizontal component is √3 times the vertical component. The angle of dip at this place is

1. π/8
2. π/6
3. π/3
4. 0

20. At a certain place, the angle of dip is 30° and the horizontal component of the Earth’s magnetic field is 0.5 oersted. The earth’s total magnetic field (in oersted) is

1. ½
2. √3
3. 1/√3
4. 1

21. A toroid of N turns, mean radius R and cross sectional radius a carries current I. It is placed on a horizontal table taken as x-y plane. Its magnetic moment m

1. is non-zero and points in the Z direction by symmetry
2. points along the axis of the toroid
3. is zero, otherwise there would be a field falling as 1/r3 at large distances outside the toroid

22. The magnetic field of 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 earth. At Mumbai, declination is nearly zero. Then

1. the declination varies between 11.3° West to 11.3° East
2. the least declination is 0°
3. the plane defined by dipole axis and the earth axis passes through Greenwich
4. declination averaged over Earth must be always negative

23. In a permanent magnet at room temperature

1. magnetic moment of each molecule is zero
2. the individual molecule have non zero magnetic moment which are all perfectly aligned
3. domains are partially aligned
4. domains are all perfectly aligned

24. The magnetic dipole moment of a current loop is independent of

1. area of the loop
2. current of the loop
3. magnetic field in which it is lying
4. number of turns

25. A circular loop carrying current of radius 100 mm is a magnetic induction of 3.6 x 10-5 T at its centre. Calculate the dipole moment

1. 15mAm2
2. 45mAm2
3. 60mAm2
4. 180 mAm2

26. The magnetic moment of a circular coil carrying current is

1. directly proportional to the square of the length of the wire in the coil
2. directly proportional to the length of the wire in the coil
3. inversely proportional to the square of the length of the wire in the coil
4. inversely proportional to the length of the wire in the coil

27. A circular current loop of magnetic moment M is in an arbitrary orientation in an external magnetic field B. The work done to rotate the loop by 30° about an axis perpendicular to its plane is

1. MBq
2. √3MB / 2
3. MB / 2
4. 0

28. Is a current carrying circular loop of radius R is placed in the x-y plane with centre at the origin. Half of the loop with x>0 if now bent so that it now lies in the y-z plane

1. the magnitude of magnetic moment now diminishes
2. the magnetic moment does not change
3. the magnitude of B at (0,0,z), z>>R increases
4. the magnitude of B at (0,0,z), z>>R is unchanged

29. The lines of force due to horizontal component of Earth’s magnetic field are

1. straight and parallel
2. concentric circles
3. parabolic
4. elliptical

30. In a plane perpendicular to magnetic meridian the dip needle will be

1. vertical
2. horizontal
3. inclined equal to the angle of dip at that place
4. pointing in and any direction

31. Earth’s magnetic field inside a closed iron box, as compared to outside is

1. more
2. less
3. same
4. zero

32. In the current (I) is flowing through a circular coil, its radius (R) and number of turns (N) in it are each doubled, the magnetic flux density at its centre becomes

1. 2 times
2. 4 times
3. 8 times
4. 6 times

33. An alpha particle and proton have same velocity when enter uniform magnetic field. The period of rotation of proton will be

1. Four times that of the alpha particle
2. One half times that of alpha particle
3. Double of that of alpha particle
4. Same as that of the alpha particle

34. Ferromagnetic substance

1. Allows all the electric field lines to pass through it
2. Repel the field lines
3. Attract the field lines
4. None of these

35. Out of diamagnetism, paramagnetism, and ferromagnetism the universal property of all substances is

1. Diamagnetism (.)
2. Paramagnetism
3. Ferromagnetism
4. Antiferromagnetism

36. How many quantities are required to specify the magnetic field of the earth

1. 1
2. 2
3. 3
4. 4

37. At the magnetic North pole of the Earth, what is the value of the angle of dip?

1. Zero
2. Minimum
3. Infinity
4. Maximum

38. Which of the following is another term for magnetisation?

1. Magnetic neutrality
2. Magnetic polarization
3. Magnetic power
4. Magnetic moment

39. Which is the incorrect statement?

1. Magnetic intensity is a vector quantity
2. Induced magnetization is a process where you can magnetize a non-magnetic material
3. Magnetic intensity and intensity of magnetization are the same
4. Total intensity is the measurement from the magnetometer after a model of the earth’s normal magnetic field is removed

40. When does a magnetic dipole possess maximum potential energy inside a magnetic field?

1. Magnetic moment and magnetic field are antiparallel (.)
2. Magnetic moment and magnetic field are parallel
3. The magnetic moment is zero
4. The magnetic field is zero

41. Calculate the surface integral of a magnetic field over a surface.

1. Maximum
2. Minimum
3. Zero
4. Equal to its magnetic flux through that surface

42. Which of the following is not a consequence of Gauss’s law?

1. The magnetic poles always exist as unlike pairs of equal strength
2. If several magnetic lines of force enter a closed surface, then an equal number of lines of force must leave that surface
3. There are abundant sources or sinks of the magnetic field inside a closed surface
4. Isolated magnetic poles do not exist

43. Which among the following is the source of the magnetic field?

1. Mechanical origin
2. Electrical origin
3. Chemical origin
4. Potential origin

44. The line of force in a magnetic field represents the direction at each point that a magnetic needle placed at the point takes up. Do they also represent the direction of the force on a moving charge at each point?

1. Not possible
2. Represent circular motion
3. Represent tangential motion
4. Represent translatory motion

45. A bar magnet of the magnetic moment 5 Am2 has poles 20 cm apart. Calculate the pole strength.

1. 250 Am
2. 4 Am
3. 100 Am
4. 25 Am

1 . (1) 2. (3) 3. (2) 4. (4) 5. (4) 6. (1) 7. (1) 8. (1) 9. (4) 10. (3) 11. (1) 12. (3) 13. (1) 14. (4) 15. (4) 16. (1) 17. (2) 18. (3) 19. (2) 20. (3) 21. (3) 22. (1) 23. (4) 24. (3) 25. (4) 26. (1) 27. (4) 28. (1) 29. (1) 30. (1) 31. (2) 32. (1) 33. (3) 34. (1) 35. (1) 36. (3) 37. (4) 38. (2) 39. (3) 40. (1) 41. (4) 42. (3) 43. (2) 44. (1) 45. (4)

## Assertion-Reasoning Based MCQ

Code

1. If both assertion and reason are true and reason is the correct explanation of assertion.
2. If both assertion and reason are true, but reason is not the correct explanation of assertion.
3. If the assertion is true, but the reason is false.
4. If the assertion is false, but the reason is true.

1 . Assertion When a magnetic dipole is placed in a non uniform magnetic field, only a torque acts on the dipole.

Reason Force wouldn’t act on dipole if magnetic field were uniform.

2. Assertion Magnetic moment of helium atom is zero.

Reason All the electron are paired in helium atom orbitals.

3. Assertion Gauss theorem is not applicable in magnetism.

Reason Mono magnetic poles do not exist.

4. Assertion The true geographic north direction is found by using a compass needle.

Reason The magnetic meridian of the earth is along the axis of rotation of the earth.

5. Assertion In the northern hemisphere the north pole of the dip needle dips downwards.

Reason The north pole of earth is as a bar magnet lies in the northern hemisphere.

6. Assertion If a compass needle be kept at magnetic north pole of the earth, the compass needle mat stay in any direction.

Reason Dip needle will stay vertical at the north pole of earth.

7. Assertion To protect any instrument from external magnetic field, it is put inside an iron box.

Reason Iron is a magnetic substance.

1 . (4)

In a non uniform magnetic field, both a torque and a net force acts on the dipole. If magnetic field were uniform, net force on dipole would be zero.

2. (1)

Helium atom has paired electrons so their electron spin are opposite to each other and hence its net magnetic moment is zero.

3. (1)

The magnetic flux through any closed surface is zero.

4. (4)

The compass needle enables us to locate magnetic north pole. If magnetic declination at that particular place is known, then true geographic north-south direction can be located. Magnetic meridian is the vertical plane passing through magnetic axis. Magnetic axis is inclined at a certain angle θ to geographical axis and earth rotates about geographic axis.

5. (3)

In the northern hemisphere, magnetic needle comes to rest along north-south direction. So, that a greater dip angle is expected in northern hemisphere.

6. (2)

At magnetic poles of the earth, the only vertical component of the earth’s field acts, horizontal component is zero. A compass needle is free to rotate in horizontal plane and is affected by horizontal component only. Thus there will be no effect on the magnetic field on the compass needle. So the needle may stop in any direction. The angle of dip at the magnetic north pole is 90° and therefore the dip needle will become vertical.

7. (2)

Iron is ferromagnetic in nature. Lines of force due to external magnetic field prefer to pass through iron.

## Case- Study Based MCQ

1 . A suspended magnet gets aligned with the earth’s magnetic field at that place. Along the equator, a suspended magnet will align horizontally. The orientation of the magnet depends on the dip angle at that place. Angle of dip is the angle between the net magnetic field of earth and the horizontal. At equator, angle of dip is 0 and at poles it is 90° . This means at equator, the earth’s magnetic field is completely horizontal and at poles. The Earth’s magnetic field is vertical.

If S is the angle of dip at a place and B is the Earth’s magnetic field, then the horizontal component of Earth’s magnetic field BH = Bcosẟ the vertical component BV = Bsinẟ

B = √(BH2 + BV2)

tan ẟ = BV / BH

(i) A magnet stands vertical at a place when suspended that place will be

(a) At equator

(b) At poles

(c) At 30° latitude

(d) At 60° latitude

(ii) The angle of dip of a face where the magnet gets aligned completely horizontal is

(a) 0°

(b) 90°

(c) 30°

(d) 45°

(iii) The horizontal and vertical components of the magnetic field at a place are √3/2B and B/2 respectively. When a magnet is left free at that place, the angle made by its magnetic axis with the horizontal is

(a) 45°

(b) 30°

(c) 60°

(d) 15°

(iv) Earth’s magnetic field always has a vertical component except at

(a) Poles

(b) Equator

(c) 30° latitude

(d) 75° latitude

(v) The magnetic field due to earth has a horizontal component of 26μT at a place where the dip is 60°. Vertical component of the field at that point is

(a) 25 μT

(b) 30 μT

(c) 45 μT

(d) 54 μT

2. The study of magnets fascinated scientists around our globe for many centuries and even now, door for research on magnets is still open. The needle in a magnetic compass or freely suspended magnet comes to rest in a position which is approximately along the geographical north-south direction of the earth.

William Gilbert in 1600 proposed that earth itself behaves like a gigantic powerful bar magnet. Goven suggested that the Earth’s magnetic field is due to hot rays coming out from the sun. These rays will heat up the air near equatorial region. Once air becomes hotter, it rises above and will move towards northern and southern hemispheres and get electrified.

This may be responsible to magnetize the ferromagnetic materials near the Earth’s surface. Till date so many theories completely explains the cause for the Earth’s magnetism.

(i) The ultimate individual unit of magnetism in any magnet is called

(a) North pole

(b) South pole

(c) Dipole

(ii) Magnetic meridian is a

(a) point

(b) horizontal plane

(c) vertical plane

(d) line along N-S

(iii) At the magnetic poles of the earth, a compass needle will be

(a) vertical

(b) bent slightly

(c) horizontal

(d) inclined at 45° to the horizontal

(iv) Due to earth’s magnetic field, the charged cosmic ray particles

(a) require greater kinetic energy to reach the equator than pole

(b) require less kinetic energy to reach the equator than pole

(c) can never reach the pole

(d) can never reach the equator

(v) Great circle on the earth’s perpendicular to the magnetic axis is

(a) magnetic meridian

(b) magnetic equator

(c) geographic meridian

(d) magnetic axis

1. (i)(b) (ii)(a) (iii)(b) (iv)(b) (v)(c)
2. (i)(c) (ii)(c) (iii)(b) (iv)(a) (v)(b)

Click Below To Learn Chemistry Term-1 Syllabus Chapters MCQs

Final Words

From the above article, you have practiced Magnetism and Matter MCQ of Class 12 Physics Chapter 5. We hope that the above mentioned latest Magnetism and Matter for Term 1 of Chapter 5 will surely help you in your exam.

If you have any doubts or queries regarding the Magnetism and Matter MCQ with answers of CBSE Class 12 Physics, feel free to reach us and we will get back to you as early as possible.

Click Below To Learn Physical Education Term-1 Syllabus Chapters MCQs

Share on:
error: Content is protected !!