Magnetism and matter practice · Medium

The magnetic moment of a magnet of length $10\;cm$ and pole strength $4.0\;Am$ will be

At a certain place, the angle of dip is 30$^ \circ$ and the horizontal component of earth’s magnetic field is 0.50 oersted. The earth’s total magnetic filed (in oersted) is

The correct definition of Meissner effect is

Statement I Time period of oscillation of two magnets, when like poles are in same direction (in a vibration magnetometer) is smaller, than the period of vibration when like poles are in opposite direction.

Statement II Moment of inertia increases in same position.
In the light of the above statements, choose the most appropriate answer from the options given below.

The incorrect statement regarding the lines of force of the magnetic field $B$ is

Assertion (A): Magnetism is relativistic.

Reason (R): When we move along with the charge, so that there is no motion relative to us, we find no magnetic field associated with the charge.

A magnet makes 40 oscillations per minute at a place having magnetic field intensity of $0.1 \times {10^{ - 5}}T$. At another place, it takes $2.5\;sec$ to complete one vibration. The value of earth’s horizontal field at that place is

A bar magnet of magnetic moment $M$ and moment of inertia $I$ is freely suspended such that the magnetic axial line is in the direction of magnetic meridian. If the magnet is displaced by a very small angle ($\mathrm{\theta }$), the angular acceleration is (Magnetic induction of earth’s horizontal field $= {B_H}$)

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

A deflection magnetometer is adjusted in the usual way. When a magnet is introduced, the deflection observed is $\mathrm{\theta }$, and the period of oscillation of the needle in the magnetometer is $T$. When the magnet is removed, the period of oscillation is ${T_0}$.Find the relation between $T\;\mathrm{and}\;{T_0}$ is

The magnetic field of a small bar magnet varies in the following manner by the influence of a magnet placed at a large distance $d$.

A bar magnet is placed north-south with its north pole due north. The points of zero magnetic field will be in which direction from center of magnet

Assertion (A): Two short magnets are placed on a cork which floats on water. The magnets are placed such that the axis of one produced bisects the axis of other at right angles. Then the cork has neither translational nor rotational motion.
Reason (R): Net force on the cork is zero.

At a temperature of $30^\circ$ C, the susceptibility of a ferromagnetic material is found to be χ$χ$. Its susceptibility at $333^\circ$ C is

The relative permeability $(\mu_r)$ of a substance is related to its susceptibility $(\chi)$ as

Susceptibility of $Mg$ at $300\;K$ is $1.2 \times {10^{ - 5}}$. The temperature at which susceptibility will be $1.8 \times {10^{ - 5}}$is

A dip circle is at right angles to the magnetic meridian.

A compass needle which is allowed to move in a horizontal plane is taken to a geomagnetic pole. It

Magnetic susceptibility for a paramagnetic and diamagnetic material is respectively

Hysteresis loss is minimized by using

A magnetic needle suspended by a silk thread is vibrating in the earth's magnetic field. if the temperature of the needle is increased by $700^{\circ} \mathrm{C}$, then

If a piece of metal was thought to be magnet, which one of the following observations would offer conclusive evidence

Assertion: If a compass needle be kept at magnetic north pole of the earth, the compass needle may stay in any direction
Reason: Dip needle will stay vertical at the north pole of earth.

Magnetic field strength due to a short bar magnet on its axial line at a distance x is B. Its value at the same distance on the equatorial line is

At a place the angle of dip is $30^\circ .$ If the horizontal component of earth’s magnetic field is ${B_H},$ then the total field intensity is

A diamagnetic material in a magnetic field moves

Consider a short magnetic dipole of magnetic length 10 cm. Its geometric length is

At which place, earth’s magnetism becomes horizontal

The magnetic induction in air at a distance $d$ from an isolated point pole of strength $m$ unit will be

A long magnet is cut into two equal parts, such that the length of each half is same as that of original magnet. If the period of original magnetic is $T$, the period of new magnet is