Magnetism and matter practice · Medium

Find the percent increase in the magnetic field $B$ when the space within a current-carrying toroid is filled with aluminium. The susceptibility of aluminium is $2.1 \times 10^{-5}$.

The absolute permeability is $8\pi \times {10^{ - 6}}\,H/m$. Its relative permeability is

The earth’s magnetic field at a certain place has a horizontal component $0.3\;gauss$ and the total strength $0.5\;gauss$. The angle of dip is

The relative permeability of iron is 5500. What is its magnetic susceptibility ?

A bar magnet when placed at an angle of $30^\circ$ to the direction of magnetic field induction of $5 \times {10^{ - 2}}\mathrm{\;T},$ experiences a moment of couple $25 \times {10^{ - 6}}\mathrm{\;N} - \mathrm{m}.$ If the length of the magnet is 5 cm, its pole strength is

A magnet of magnetic moment $M$ is freely suspended in a uniform magnetic field strength B. The work done is deflecting the magnet through an angle $\theta$ is given by

At a certain place the horizontal component of the earth’s magnetic field is ${B_0}$ and the angle of dip is 45$^ \circ$. The total intensity of the field at that place will be

A short bar magnet is placed in a horizontal plane with its axis in the magnetic meridian. Null points are found on its equatorial line (i.e., its normal bisector) at $12.5 \mathrm{~cm}$ from the centre of the magnet. The earth's magnetic field at the place is $0.38\,\mathrm{G}$ and the angle of dip is zero. Locate the null points when the magnet is turned around by $180^{\circ}$. Assume that the length of the magnet is negligible as compared to the distance of the null-points from the centre of the magnet.

Resultant force acting on a diamagnetic material in a magnetic field is in direction

Assertion(A): The ferro magnetic substances do not obey curie's law.

Reason(R): At curie point ferro magnetic substances start behaving as a para magnetic substances.

A copper rod is suspended a non homogenous magnetic field region. The rod when in equilibrium will align itself

A vibration magnetometer consists of two identical bar magnets placed one over the other such that they are perpendicular and bisect each other. The time period of oscillation in a horizontal magnetic field is ${2^{5/4}}$ second. One of the magnets is removed and if the other magnet oscillates in the same field, then the time period in second is

The SI unit of magnetizing field is;

A specimen of iron of permeability $8 \times 10^{-3}$ weber/amp $\times$ metre is placed in a magnetic field of strength $160 \mathrm{amp} /$ metre. Then magnetic induction in this iron is -

To shield an instrument from external magnetic field, it is placed inside a cabin made of

Consider the following statements:

1. Magnetisation can be increased without limit by applying strong magnetizing fields.

2. Magnetisation is maximum at $0 \mathrm{~K}$.

Which of the statements given above is/are correct in respect of a ferromagnetic material?

Susceptibility of a material is 100 then material will be:

Statement I The ferromagnetic property depends on temperature. At high temperature, ferromagnetic becomes paramagnet.
Statement II At high temperature, the domain wall area of a ferromagnetic substance increases.
In the light of the above statements, choose the most appropriate answer from the options given below.

Assertion(A): It is not necessary that every magnet has one north pole and one south pole.

Reason(R): It is a basic fact that magnetic mono poles exists.

With a standard rectangular bar magnet of length $\left( l \right)$, breadth $(b;\;b < < l)$ and magnetic moment $M$, the time period of the magnet in vibration magnetometer is 4 s. If the magnet is cut normal to its length into four equal pieces, the time period (in second) with one of the pieces

In a ferromagnetic material, below the Curie temperature, a domain is defined as

The ration of intensities of magnetic field on the axial line and on equatorial line of a small bar magnet if magnetic moment at the same distance will be

The total intensity of earth's magnetic field at the poles is 7 units. Its value at the equator is

Which of these materials requires the least
value of magnetic field strength to magnetise
it?

The magnetising field required to be applied in opposite direction to reduce residual magnetism to zero is called

The relative permeability is represented by $\mu_{\mathrm{r}}$ and the susceptibility by $\chi$ for a magnetic substance. Then for a paramagnetic substance.

The time period of a freely suspended magnet does not depend upon

A bar magnet made of steel has a magnetic moment of $2.5 \mathrm{~Am}^2$ and a mass of $6.6 \times 10^3 \mathrm{~kg}$. If the density of steel is $7.9 \times 10^9 \mathrm{~kg} / \mathrm{m}^3$, find the intensity of magnetization of the magnet.

Which of the following is represented by the area enclosed by a hysteresis loop ($B - H$ curve)?

Which one of the following characteristics is not associated with a ferromagnetic material?