Advertisements
Advertisements
Question
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.
Advertisements
Solution
Given: Magnetic moment of the bar magnet, M = 0.48 J T−1
Distance, d = 10 cm = 0.1 m
(a) The magnetic field at a distance d from the centre of the magnet on the axis is given by the relation:
B = `μ_0/(4pi) (2M)/d^3`
Where,
μ0 = Permeability of free space = 4π × 10−7 T mA−1
∴ B = `(4pi xx 10^-7 xx 2 xx 0.48)/(4pi xx (0.1)^3)`
= 0.96 × 10−4 T
= 0.96 G
The magnetic field is along the S-N direction.
(b) The magnetic field at a distance of 10 cm (i.e., d = 0.1 m) on the equatorial line of the magnet is given as:
B = `(μ_0 xx M)/(4pi xx d^3)`
= `(4pi xx 10^-7 xx 0.48)/(4pi (0.1)^3)`
= 0.48 G
The magnetic field is along the N-S direction.
RELATED QUESTIONS
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]
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.
Explain Curie’s law for a paramagnetic substance.
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?
What happens to a ferromagnetic material when its temperature increases above curie temperature?
For a paramagnetic substance, the magnetic susceptibility is ______.
All atoms of a magnetic substance have a resultant magnetic moment even in absence of external magnetic field. The substance is ______.
Magnetic material can be easily magnetized if magnetic susceptibility is ______.
A certain region of space is to be shielded from magnetic fields. Suggest a method.
Nickel shows ferromagnetic property at room temperature. If the temperature is increased beyond curie temperature, then it will show ______.
The coercivity of a small magnet where the ferromagnet gets demagnetized is 3 × 103 Am–1. The current required to be passed in a solenoid of length 10 cm and number of turns 100, so that the magnet gets demagnetized when inside the solenoid, is ______.
The magnetic susceptibility for diamagnetic materials is ______.
Earth's magnetic field analyses has a horizontal component except at:-
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 ______.
Explain ferromagnetism on the basis of the domain theory.
Explain the Domain theory in brief.
