Advertisements
Advertisements
Question
A Rowland ring of mean radius 15 cm has 3500 turns of wire wound on a ferromagnetic core of relative permeability 800. What is the magnetic field B in the core for a magnetising current of 1.2 A?
Advertisements
Solution
Mean radius of a Rowland ring, r = 15 cm = 0.15 m
Number of turns on a ferromagnetic core, N = 3500
Relative permeability of the core material, μr = 800
Magnetising current, I = 1.2 A
The magnetic field is given by the relation:
B = `(μ_"r"μ_0"IN")/(2π"r")`
Where,
μ0 = Permeability of free space = 4π × 10−7 T mA−1
B = `(800 xx 4π xx 10^-7 xx 1.2 xx 3500)/(2π xx 0.15)`
= 4.48 T
Therefore, the magnetic field in the core is 4.48 T.
APPEARS IN
RELATED QUESTIONS
The susceptibility of magnesium at 200 K is 1.8 x 10-5. At what temperature will the susceptibility decrease by 6 x 10-6?
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.
Explain Curie’s law for a paramagnetic substance.
Identify the following magnetic materials :
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)
All atoms of a magnetic substance have a resultant magnetic moment even in absence of external magnetic field. The substance is ______.
A sphere of gold when brought towards a powerful magnet experiences ____________.
Is the permeability of a ferromagnetic material independent of the magnetic field? If not, is it more for lower or higher fields?
Earth's magnetic field analyses has a horizontal component except at:-
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.
A uniform magnetic field gets modified as shown in figure when two specimens A and B are placed in it.
 |
 |
| (a) | (b) |
- Identify the specimen A and B.
- How is the magnetic susceptibility of specimen A different from that of specimen B?
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 ______.
The relative magnetic permeability of a substance X is slightly less than unity and that of substance Y is slightly more than unity, then ______.
Explain the Domain theory in brief.
On what basis are materials broadly classified into diamagnetic, paramagnetic, and ferromagnetic groups?
What happens to paramagnetic substances on cooling at the Curie temperature?
Which mathematical relation expresses Weiss Law for ferromagnetic substances above the Curie temperature?
