Magnetic Properties of Matter
OBJECTIVE-II
1. Pick the correct options.
(a) All electrons have magnetic moments.
(b) All protons have magnetic moments.
(c) All nuclei have a magnetic moment.
(d) All atoms have a magnetic moment.
ANSWER: (a), (b).
EXPLANATION: Electrons in an atom move about the nucleus in closed paths and hence constitute electric current loops. As current loops have a magnetic dipole moment, each electron has a magnetic moment due to its orbital motion. Also due to spin and resulting angular momentum each electron has a permanent magnetic moment. Option (a) is correct.
All protons have also a magnetic moment. Option (b) is correct.
Some nuclei may have a magnetic moment but not all. Similarly, in a number of atoms, the resultant magnetic moment is zero. So all atoms do not have a magnetic moment. Options (c) and (d) are incorrect.
2. Permanent magnetic moment of the atoms of a material is not zero. The material
(a) must be paramagnetic
(b) must be diamagnetic.
(c) must be ferromagnetic.
(d) may be paramagnetic.
ANSWER: (d)
EXPLANATION: Such material may be paramagnetic or ferromagnetic. It is not the condition for a sure paramagnetic material. Option (d) is correct.
3. The permanent magnetic moment of the atoms of material is zero. The material
(a) must be paramagnetic
(b) must be diamagnetic.
(c) must be ferromagnetic.
(d) may be paramagnetic.
ANSWER: (b)
EXPLANATION: In this case, there will be an induced dipole magnetic moment in the atoms when kept in a magnetic field. From Lenz's law, this induced magnetic moment will oppose the original field. The resultant field in such materials is, therefore, smaller than the applied field. This phenomenon is diamagnetism. Option (b) is correct.
4. Which of the following pairs has quantities of the same dimensions?
(a) magnetic field B and magnetizing field intensity H
(b) magnetic field B and intensity of magnetization.
(c) magnetizing field intensity H and intensity of magnetization I.
(d) longitudinal strain and magnetic susceptibility.
ANSWER: (c), (d).
EXPLANATION: H and I are intensities. Their dimensions are the same. Option (c) is correct.
Longitudinal strain is a dimensionless quantity. Susceptibility is a proportionality constant between H and I, both having the same dimensions. Thus susceptibility is also dimensionless. Option (d) is correct.
5. When a ferromagnetic material goes through a hysteresis loop, the magnetic susceptibility
(a) has a fixed value
(b) maybe zero
(c) maybe infinity
(d) maybe negative.
ANSWER: (b), (c), (d).
EXPLANATION: Since the magnetic susceptibility =I/H, this ratio may sometimes be zero and sometimes infinity when the material goes through a hysteresis loop. It is because there comes a stage when I = zero but H is non-zero and also sometimes it is the opposite. Hence options (b) and (c) are correct.
It may also be negative sometimes because H and I may have opposite directions. Option (d) is correct.
6. Mark out the correct options.
(a) Diamagnetism occurs in all materials
(b) Diamagnetism results from the partial alignment of the permanent magnetic moment.
(c) The magnetizing field intensity H is always zero in free space.
(d) The magnetic field of the induced magnetic moment is opposite to the applied field.
ANSWER: (a), (d).
EXPLANATION: Diamagnetism occurs due to induced magnetic moments that are opposite to the original field according to Lenz's law. And it happens in all materials. So options (a) and (d) are correct, option (b) is incorrect.
In a vacuum, I = zero. The magnetizing field intensity
H =B/µₒ -I
=B/µₒ, may not be zero. Option (c) is incorrect.
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Links to the Chapters
Links to the Chapters
CHAPTER- 37- Magnetic Properties of MatterCHAPTER- 36- Permanent Magnets
CHAPTER- 35- Magnetic Field due to a Current
CHAPTER- 34- Magnetic Field
CHAPTER- 33- Thermal and Chemical Effects of Electric Current
CHAPTER- 37- Magnetic Properties of Matter
CHAPTER- 36- Permanent Magnets
CHAPTER- 35- Magnetic Field due to a Current
CHAPTER- 34- Magnetic Field
CHAPTER- 33- Thermal and Chemical Effects of Electric Current
CHAPTER- 32- Electric Current in ConductorsCHAPTER- 31- CapacitorsCHAPTER- 30- Gauss's Law
CHAPTER- 29- Electric Field and Potential
CHAPTER- 28- Heat Transfer
OBJECTIVE -I
CHAPTER- 26-Laws of Thermodynamics
CHAPTER- 25-CALORIMETRY
Questions for Short Answer
OBJECTIVE-I
OBJECTIVE-II
EXERCISES - Q-11 to Q-18
CHAPTER- 24-Kinetic Theory of Gases
CHAPTER- 23 - Heat and Temperature
CHAPTER- 21 - Speed of Light
CHAPTER- 20 - Dispersion and Spectra
CHAPTER- 19 - Optical Instruments
CHAPTER- 18 - Geometrical Optics
CHAPTER- 17 - Light Waves
CHAPTER- 16 - Sound Waves
CHAPTER- 15 - Wave Motion and Waves on a String
CHAPTER- 14 - Fluid Mechanics
CHAPTER- 13 - Fluid Mechanics
CHAPTER- 12 - Simple Harmonic Motion
CHAPTER- 11 - Gravitation
CHAPTER- 10 - Rotational Mechanics
CHAPTER- 9 - Center of Mass, Linear Momentum, Collision
CHAPTER- 32- Electric Current in Conductors
CHAPTER- 31- Capacitors
CHAPTER- 30- Gauss's Law
CHAPTER- 29- Electric Field and Potential
CHAPTER- 28- Heat Transfer
CHAPTER- 26-Laws of Thermodynamics
CHAPTER- 25-CALORIMETRY
Questions for Short Answer
OBJECTIVE-I
OBJECTIVE-II
CHAPTER- 24-Kinetic Theory of Gases
CHAPTER- 23 - Heat and Temperature
CHAPTER- 21 - Speed of Light
CHAPTER- 20 - Dispersion and Spectra
CHAPTER- 19 - Optical Instruments
CHAPTER- 18 - Geometrical Optics
CHAPTER- 17 - Light Waves
CHAPTER- 16 - Sound Waves
CHAPTER- 15 - Wave Motion and Waves on a String
CHAPTER- 14 - Fluid Mechanics
CHAPTER- 13 - Fluid Mechanics
CHAPTER- 12 - Simple Harmonic Motion
CHAPTER- 11 - Gravitation
CHAPTER- 10 - Rotational Mechanics
CHAPTER- 9 - Center of Mass, Linear Momentum, Collision
CHAPTER- 8 - Work and Energy
Click here for → Question for Short Answers
Click here for → OBJECTIVE-I
Click here for → OBJECTIVE-II
Click here for → Exercises (1-10)
Click here for → Question for Short Answers
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Click here for → OBJECTIVE-II
Click here for → Exercises (1-10)
Click here for → Exercises (11-20)
CHAPTER- 7 - Circular Motion
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Click here for → OBJECTIVE-II
Click here for → EXERCISES (11-20)
Click here for → EXERCISES (21-30)
CHAPTER- 6 - Friction
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Click here for → OBJECTIVE-I
Click here for → OBJECTIVE-II
Click here for → EXERCISES (11-20)
Click here for → EXERCISES (21-30)
CHAPTER- 6 - Friction
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Click here for → Questions for Short Answer
Click here for → OBJECTIVE-I
Click here for → Friction - OBJECTIVE-II
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Click here for → EXERCISES (21-31)
Click here for → OBJECTIVE-I
Click here for → Friction - OBJECTIVE-II
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Click here for → Exercises (11-20)
Click here for → EXERCISES (21-31)
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CHAPTER- 5 - Newton's Laws of Motion
Click here for → QUESTIONS FOR SHORT ANSWER
Click here for → QUESTIONS FOR SHORT ANSWER
Click here for→ Newton's laws of motion - Objective - I
Click here for → Newton's Laws of Motion - Objective -II
Click here for → Newton's Laws of Motion-Exercises(Q. No. 1 to 12)
Click here for→ Newton's laws of motion - Objective - I
Click here for → Newton's Laws of Motion - Objective -II
Click here for → Newton's Laws of Motion-Exercises(Q. No. 1 to 12)
Click here for→Newton's Laws of Motion,Exercises(Q.No. 13 to 27)
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CHAPTER- 4 - The Forces
The Forces-
"Questions for short Answers"
Click here for "The Forces" - OBJECTIVE-I
Click here for "The Forces" - OBJECTIVE-II
Click here for "The Forces" - Exercises
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CHAPTER- 3 - Kinematics - Rest and Motion
Click here for "Questions for short Answers"
Click here for "OBJECTIVE-I"
Click here for EXERCISES (Question number 1 to 10)
Click here for EXERCISES (Question number 11 to 20)
Click here for EXERCISES (Question number 21 to 30)
Click here for EXERCISES (Question number 31 to 40)
Click here for EXERCISES (Question number 41 to 52)
CHAPTER- 2 - "Physics and Mathematics"
CHAPTER- 2 - "Physics and Mathematics"
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