Advertisements
Advertisements
प्रश्न
Distinguish between ‘paramagnetic’ and ‘ferromagnetic’ substances.
उत्तर
| Paramagnetic | Ferromagnetic |
| Substances which are weakly attracted by a magnet are called paramagnetic substances. | Substances which are strongly attracted by a magnet are called ferromagnetic substances. |
| Paramagnetic materials lose their magnetism on removal of the external field and hence cannot be used to make permanent magnets. | Ferromagnetic materials retain some magnetism on removal of external field and hence can be used to make permanent magnets. |
| The susceptibility is positive but small. | The susceptibility is positive but very high. |
| In the absence of electric field, the net dipole moment is zero. | In the absence of electric field, the net dipole moment is non-zero. |
| Aluminium, manganese, chromium and platinum are some examples of paramagnetic substances. | Iron, nickel, cobalt, gadolinium, dysprosium and their alloys are some examples of ferromagnetic substances. |
APPEARS IN
संबंधित प्रश्न
Give any ‘two’ points of differences between diamagnetic and ferromagnetic substances.
An iron rod of the area of cross-section 0.1m2 is subjected to a magnetizing field of 1000 A/m. Calculate the magnetic permeability of the iron rod. [Magnetic susceptibility of iron = 59.9, magnetic permeability of vacuum = 4π x 10-7 S. I. unit]
In what way is the behaviour of a diamagnetic material different from that of a paramagnetic, when kept in an external magnetic field?
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
A meter gauge train is heading north with speed 54 km/hr in earth's magnetic field 3 x 10-4T. The e.m.f. induced across the axle joining the wheels is ..........
(a) 0.45 mV
(b) 4.5 mV
(c) 45 mV
(d) 450 m V
Which of the following substances are para-magnetic?
Bi, Al, Cu, Ca, Pb, Ni
The susceptibility of a magnetic material is − 2.6 × 10−5. Identify the type of magnetic material and state its two properties.
The relative magnetic permeability of a magnetic material is 800. Identify the nature 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?
Identify the following magnetic materials :
Which of the following statements is correct for diamagnetic materials?
Choose the correct option:
A rectangular magnet suspended freely has a period of oscillation equal to T. Now it is broken into two equal halves (each having half of the original length) and one piece is made to oscillate freely. Its period of oscillation is T′, the ratio of T′/T is ______.
Choose the correct option:
A magnetising field of 360 Am−1 produces a magnetic flux density (B) = 0.6T in a ferromagnetic material. What is its permeability in Tm A−1?
A paramagnetic gas has 2.0 × 1026 atoms/m with atomic magnetic dipole moment of 1.5 × 10−23 A m2 each. The gas is at 27°C.
- Find the maximum magnetization intensity of this sample.
- If the gas in this problem is kept in a uniform magnetic field of 3 T, is it possible to achieve saturation magnetization? Why?
The susceptibility of a paramagnetic material is χ at 27° C. At what temperature its susceptibility be χ/3?
A rod of magnetic material of cross-section 0.25 cm2 is placed in a magnetizing field of intensity 4000 A/m-1. The magnetic flux passing through the rod is 25 × 10-6 Wb. Find out
(a) relative permeability
(b) magnetic susceptibility and
(c) magnetisation of the rod.
A domain in a ferromagnetic substance is in the form of a cube of side 1 µm. If it contains 8 × 1010 atoms and each atomic dipole has a dipole moment of 9 × 10-24 Am2 then the magnetisation of the domain is ______.
For a paramagnetic substance, the magnetic susceptibility is ______.
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?
There are three needles 'N1', 'N2' and 'N3' made of a ferromagnetic, a paramagnetic and a diamagnetic substance respectively. When a magnet is brought close to them, then it will ____________.
The materials having negative magnetic susceptibility are ____________.
The magnetic property of magnetic substance is associated with ____________.
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?
Explain qualitatively on the basis of domain picture the irreversibility in the magnetisation curve 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?
Metals getting magnetised by orientation of atomic magnetic moments in external magnetic field are called ______.
When a ferromagnetic material is created above its curie temperature
Earth's magnetic field analyses has a horizontal component except at:-
A hydrogen atom is paramagnetic. A hydrogen molecule is
Most of the substance show which of the magnetic property:-
If a charged particle at rest experience no electromagnetic force
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.
A permanent magnet in the shape of a thin cylinder of length 10 cm has M = 106 A/m. Calculate the magnetisation current IM.
From molecular view point, discuss the temperature dependence of susceptibility for diamagnetism, paramagnetism and ferromagnetism.
If the magnetizing field on a ferromagnetic material is increased, its permeability ______.
Which of the following has a permeability less than that of free space?
Which of the following cannot modify an external magnetic field as shown in the figure?
The relative magnetic permeability of a substance X is slightly less than unity and that of substance Y is slightly more than unity, then ______.
