Paramagnetism

Q. 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

1. $\frac{{\mu }_0}{4\pi }\frac{M}{d^3}$
2. $\frac{{\mu }_0}{4\pi }\frac{M\sqrt{2}}{d^3}$
3. $\frac{{\mu }_0}{4\pi }\frac{2\sqrt{2}M}{d^3}$
4. $\frac{{\mu }_0}{4\pi }\frac{2M}{d^3}$

Q.

A paramagnetic sample shows a net magnetization of $6A/m$ when it is placed in an external magnetic field of $0.4T$ at a temperature of $4K$. When the sample is placed in an external magnetic field of $0.3T$ at a temperature of $24K$, then the magnetization will be:

1. $4A/m$

2. $1A/m$

3. $0.75A/m$

4. $2.25A/m$

Q. A magnet of magnetic dipole moment M is released in a uniform magnetic field of induction B from the position shown in the figure. Find its maximum kinetic energy during motion.

1. $MB$
2. $\frac{MB}{2}$
3. $\frac{3MB}{2}$
4. $2MB$

Q. Show diagrammatically the behaviour of magnetic field lines in the presence of (i) paramagnetic and (ii) diamagnetic substances. How does one explain this distinguishing feature?

Q. Answer the following questions:(a) Why does a paramagnetic sample display greater magnetisation(for the same magnetising field) when cooled? (b) Why is diamagnetism, in contrast, almost independent oftemperature? (c) If a toroid uses bismuth for its core, will the field in the core be(slightly) greater or (slightly) less than when the core is empty? (d) Is the permeability of a ferromagnetic material independent ofthe magnetic field? If not, is it more for lower or higher fields? (e) Magnetic field lines are always nearly normal to the surface of aferromagnet at every point. (This fact is analogous to the staticelectric field lines being normal to the surface of a conductor atevery point.) Why? (f ) Would the maximum possible magnetisation of a paramagneticsample be of the same order of magnitude as the magnetisationof a ferromagnet?

Q. 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

1. $\frac{{\mu }_0}{4\pi }\frac{M}{d^3}$
   
2. $\frac{{\mu }_0}{4\pi }\frac{M\sqrt{2}}{d^3}$
   
3. $\frac{{\mu }_0}{4\pi }\frac{2\sqrt{2}M}{d^3}$
4. $\frac{{\mu }_0}{4\pi }\frac{2M}{d^3}$

Q. A sample of paramagnetic salt contains 2.0 × 1024 atomic dipoleseach of dipole moment 1.5 × 10–23 J T–1. The sample is placed undera homogeneous magnetic field of 0.64 T, and cooled to a temperatureof 4.2 K. The degree of magnetic saturation achieved is equal to 15%.What is the total dipole moment of the sample for a magnetic field of0.98 T and a temperature of 2.8 K? (Assume Curie’s law)

Q. What do u mean by maGnetism & matter

Q. Discuss the Curie law for paramagnetic material.

Q. Copper is :

1. Paramagnetic
2. Diamagnetic
3. Ferromagnetic
4. None of these

Q. A sample of the paramagnetic salt to which the magnetization
curve of Figure applies is to be tested to see whether it obeys
Curie’s law. The sample is placed in a uniform $0.50$ T magnetic field
that remains constant throughout the experiment. The magnetization M is then measured at temperatures ranging from $10$ to $300$ K.
Will it be found that Curie’s law is valid under these conditions?

Q.

Which of the following statements are correct?

1. Atoms of paramagnetic material doesn’t have a net dipole moment

2. Diamagnetic material moves towards the region of lower magnetic field

3. Paramagnetic material moves towards the region of lower magnetic field

4. Atoms of Diamagnetic material have a net dipole moment

Q. Which of these materials have atoms with a net magnetic moment?

1. Diamagnetic
2. Paramagnetic
3. Ferromagnetic
4. None of these

Q. The saturation magnetization $M_{max}$ of the ferromagnetic metal nickel is $4.70\times {10}^{5}A/m$. Calculate the magnetic dipole moment of a single nickel atom. (The density of nickel is $8.90g/c{m}^3$ and its molar mass is $58.71g/mol$.)

Q. Consider the following statements I and II.
(I) Paramagnetism is explained by domain theory
(II) Susceptibility of a diamagnetic substance is independent of temperature.
Identify the correct choice from the following.

1. Both I and II are correct
2. Both I and II are incorrect
3. I is correct and II is incorrect.
4. I is incorrect and II is correct

Q. 17.How the net dipole moment of an atom for diamagnetic material is zero?

Q. 4.How frog is said to be diamagnetic?

Q. The most appropriate magnetization $M$ versus magnetising field $H$ curve for a paramagnetic substance is

1. $A$
2. $B$
3. $C$
4. $D$

Q. According to Curie's law, the magnetic susceptibility of a substance at an absolute temperature T is proportional to

1. T
2. $1/T^2$
3. $T^2$
4. $1/T$

Q. The figure gives the magnetization curve for a paramagnetic material. The vertical axis scale is set by $a=0.15$, and the horizontal axis scale is set by $b=0.2$ T/K. Let ${\mu }_{sam}$ be the measured net magnetic moment of a sample of the material and ${\mu }_{max}$ be the maximum possible net magnetic moment of that sample.According to Curie’s law, what would be the ratio ${\mu }_{sam}/{\mu }_{max}$ were the sample placed in a uniform magnetic field of magnitude $0.800$ T, at a temperature of $2.00$ K?