Advertisements
Advertisements
प्रश्न
The susceptibility of a paramagnetic material is χ at 27° C. At what temperature its susceptibility be χ/3?
Advertisements
उत्तर
Data: χm1 = χ, T1 = 27°C = 300 K, χm2 = `χ/3`
By Curie's law,
`"M"_"z" = "C" "B"_0/"T"`
Since Mz = χmH and B0 = μ0H
χmH = C`(mu_0"H")/"T"`
∴ χm = C `mu_0/"T"`
∴ χm ∝ `1/"T"`
∴ `(chi_"m1")/(chi_"m2") = "T"_2/"T"_1`
∴ `"T"_2 = (chi_"m1")/(chi_"m2") xx "T"_1 = 3 chi/chi xx 300 = 900 "K" = 627^circ "C"`
APPEARS IN
संबंधित प्रश्न
Distinguish between ‘paramagnetic’ and ‘ferromagnetic’ substances.
Out of the two magnetic materials, 'A' has relative permeability slightly greater than unity while 'B' has less than unity. Identify the nature of the materials 'A' and 'B'. Will their susceptibilities be positive or negative?
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?
Distinguish between diamagnetic and paramagnetic substances.
The magnetic susceptibility of annealed iron at saturation is 4224. Find the permeability of
annealed iron at saturation. (μ0 = 4Π × 10−7 SI unit)
The susceptibility of a magnetic material is 0·9853. Identify the type of magnetic material. Draw the modification of the field pattern on keeping a piece of this material in a uniform magnetic field.
The susceptibility of a magnetic material is − 2.6 × 10−5. Identify the type of magnetic material and state its two properties.
Draw magnetic field line when a (i) diamagnetic, (ii) paramagnetic substance is placed in an external magnetic field. Which magnetic property distinguishes this behaviour of the field line due to the substances?
A tangent galvanometer shows a deflection of 45° when 10 mA of current is passed through it. If the horizontal component of the earth's magnetic field is `B_H = 3.6 xx 10^-5 "T"` and radius of the coil is 10 cm, find the number of turns in the coil.
Two substances A and B have their relative permeability slightly greater and slightly less than 1 respectively. What do you conclude about A and B as far as their magnetic materials are concerned?
Answer the following question.
Write three points of differences between para-, dia- and ferromagnetic materials, giving one example for each.
Which of the following statements is correct for diamagnetic materials?
What happens to a ferromagnetic material when its temperature increases above curie temperature?
Answer in brief.
Discuss the Curie law for paramagnetic material.
Two identical bar magnets each of magnetic moment M, separated by some distance are kept perpendicular to each other. The magnetic induction at a point at the same distance d from the centre of magnets, is (µ0 = permeability of free space)
The susceptibility of a magnetic material is positive and small. The material is ______.
The magnetic susceptibility of a paramagnetic material at - 73 °C is 0.0075. Its value at -173 °C will be ______.
Magnetization of the sample is ______.
If a magnetic field is applied to a liquid in one arm of a narrow U-tube, the liquid level in that arm is lowered. The liquid in U-tube arm is ______.
Relative permittivity and permeability of a material are `epsilon_"r"` and `µ_"r"` respectively. Which of the following values of these quantities are allowed for a diamagnetic material?
The product of magnetic susceptibility (`chi`) and absolute temperature (T) is constant for a ____________.
A small quantity of paramagnetic liquid is taken in a watch - glass and kept on two dissimilar magnetic poles. The liquid ____________.
The earth’s field departs from its dipole shape substantially at large distances (greater than about 30,000 km). What agencies may be responsible for this distortion?
A short bar magnet has a magnetic moment of 0.48 J T−1. Give the direction and magnitude of the magnetic field produced by the magnet at a distance of 10 cm from the centre of the magnet on
- the axis,
- the equatorial lines (normal bisector) of the magnet.
Why does a paramagnetic sample display greater magnetisation (for the same magnetising field) when cooled?
Why is diamagnetism, in contrast, almost independent of temperature?
Is the permeability of a ferromagnetic material independent of the magnetic field? If not, is it more for lower or higher fields?
Magnetic field lines are always nearly normal to the surface of a ferromagnet at every point. (This fact is analogous to the static electric field lines being normal to the surface of a conductor at every point.) Why?
Would the maximum possible magnetisation of a paramagnetic sample be of the same order of magnitude as the magnetisation of a ferromagnet?
What kind of ferromagnetic material is used for coating magnetic tapes in a cassette player, or for building ‘memory stores’ in a modern computer?
Assertion: A paramagnetic sample display greater magnetisation (for the same magnetic field) when cooled.
Reason: The magnetisation does not depend on temperature.
Which of the following property shows the property of ferromagnetic substances?
Two identical bar magnets are fixed with their centres at a distance d apart. A stationary charge Q is placed at P in between the gap of the two magnets at a distance D from the centre O as shown in the figure. The force on the charge Q is ______.
The magnetic susceptibility for diamagnetic materials is ______.
For a diamagnetic material
Most of the substance show which of the magnetic property:-
The universal property of all substances is ______.
S is the surface of a lump of magnetic material.
- Lines of B are necessarily continuous across S.
- Some lines of B must be discontinuous across S.
- Lines of H are necessarily continuous across S.
- Lines of H cannot all be continuous across S.
A long solenoid has 1000 turns per metre and carries a current of 1 A. It has a soft iron core of µr = 1000. The core is heated beyond the Curie temperature, Tc.
- The H field in the solenoid is (nearly) unchanged but the B field decreases drastically.
- The H and B fields in the solenoid are nearly unchanged.
- The magnetisation in the core reverses direction.
- The magnetisation in the core diminishes by a factor of about 108.
Explain quantitatively the order of magnitude difference between the diamagnetic susceptibility of N2 (~5 × 10–9) (at STP) and Cu (~10–5).
From molecular view point, discuss the temperature dependence of susceptibility for diamagnetism, paramagnetism and ferromagnetism.
An ammeter of resistance R gives a full-scale deflection when a current of 2 A passes through it. If it is measured with a maximum current of 10 A, the required shunt is ______.
- Assertion (A): Diamagnetic substances exhibit magnetism.
- Reason (R): Diamagnetic materials do not have a permanent magnetic dipole moment.
Which of the following has a permeability less than that of free space?
Explain the Domain theory in brief.
Explain the meaning of the following statement:
Curie temperature for soft iron is 770°C.
