Magnetism and matter practice · Mixed difficulty

A bar magnet of magnetic moment ${10^4}J/T$ is free to rotate in a horizontal plane. The work done in rotating the magnet slowly from a direction parallel to a horizontal magnetic field of $4 \times {10^{ - 5}}T$ to a direction $60^\circ$ from the field will be

The work done in turning a magnet of magnetic moment ‘$M$’ by an angle of $90^\circ$ from the meridian is ‘$n$’ times the corresponding work done to turn it through an angle at $60^\circ$, when ‘$n$’ is given by

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

A paramagnetic substance of susceptibility $3\mathrm{ } \times \mathrm{ }{10^{ - 4}}$ is placed in a magnetic intensity of $4\mathrm{ } \times \mathrm{ }{10^{ - 4}}A{m^{ - 1}}$ . Then the intensity of magnetization (in the units of $A{m^{ - 1}}$) is

If the strength of the magnetic field is increased by the frequency of a magnetic needle oscillating in that field.

The magnetic moment of atomic neon is equal to

Earth's magnetic field has no vertical
component :

Above the curie temperature the susceptibility
of ferromagnetic substance varies

When a ferromagnetic material is heated to temperature above its curie point, the material

A dip circle is oriented with its plane at an angle of $30^{\circ}$ with the magnetic meridian at a place.
The apparent angle of dip shown by the dip circle is $45^{\circ}.$ The true angle of dip at the place will be

Which of the following magnetic material is temperature dependent?

A magnet performs 10 oscillations per minute in a horizontal plane at a place where the angle of dip is 45$^ \circ$ and the total intensity is 0.707 CGS units. The number of oscillations per minute at a place where dip angle is 60$^ \circ$ and total intensity is 0.5 CGS units will be

Which among the following have negative susceptibility?

The relation between $B,H\mathrm{\;and}\;I$ in SI unit is

Aurora Borealis is a luminous electrical discharge in the upper layers of the atmosphere, which is visible more frequently in

Diamagnetic substances are

Select the correct statement from the following

The direction of Earth's magnetic field at the magnetic poles is

A vibration magnetometer is placed at south pole, then the time period will be

The magnetic induction and magnetising field intensity in a sample of magnetic material are $\mathrm{B}$ and $\mathrm{H}$ respectively. The magnetic susceptibility of the material is:

Choose the correct statement

A magnetic needle is placed with its north pole
facing north in north south direction. In its
map of magnetic field the null point will be

A deflection magnetometer works on

In sum and difference method vibration magnetometer, the time period is more if

Among the following properties describing diamagnetism identify the property that is wrongly stated

Assume that each iron atom has a permanent magnetic moment equal to $2\, \mathrm{Bohr}$ magnetons (1 Bohr magneton equals $9.27 \times 10^{-24} \mathrm{~A} \mathrm{~m}^2$ ). The density of atoms in iron is $8.52 \times 10^{28}$ atoms $\mathrm{m}^{-3}$. (a) Find the maximum magnetization $I$ in a long cylinder of iron. (b) Find the maximum magnetic field $B$ on the axis inside the cylinder.

The area of hysteresis loop of a material is equivalent to $250\;joule$. When $10\;kg$ material is magnetized by an alternating field of $50\;Hz$ then energy lost in one hour will be (density of material is $7.5\;gm/c{m^3}$)

The bob of a simple pendulum is replaced by a magnet. The oscillation are set along the length of the magnet. A copper coil is added so that one pole of the magnet passes in and out of the coil. The coil is short-circuited. Then which one of the following happens

A superconducting material is

The coil in a tangent galvanometer is 16 cm in radius. If a current of 20 mA is to produce a deflection of $45^\circ$ then the number of turns wound on it, is (Take horizontal component of earth’s magnetic field$= 0.36 \times {10^{ - 4}}\mathrm{\;T\;and\;}{\mathrm{\mu }_0} = 4\pi \times {10^{ - 7}}\;\mathrm{Wb\;}{\mathrm{A}^{ - 1}}\mathrm{\;}{\mathrm{m}^{ - 1}}$