Magnetism and matter practice · Medium

Which of the following statements are correct?
A. Electric monopoles do not exist, whereas magnetic monopoles exist.
B. Magnetic field lines due to a solenoid at its ends and outside cannot be completely straight and confined.
C. Magnetic field lines are completely confined within a toroid.
D. Magnetic field lines inside a bar magnet are not parallel.
E. $\chi = - 1$ is the condition for a perfect diamagnetic material, where $\chi$ is its magnetic susceptibility.
Choose the correct answer from the options given below.

For a vibration magnetometer, the time period of suspended bar magnet can be reduced by

A bar magnet is $0.10 \mathrm{~m}$ long and its pole strength is $12\,\mathrm{Am}$. Find the magnitude of the magnetic field at a point on its axis at a distance of $20 \mathrm{~cm}$ from it.

A magnetic field strength $(\mathrm{H}) 3 \times 10^3 \mathrm{Am}^{-1}$ produces a magnetic field of induction (B) of $12 \pi \mathrm{T}$ in an iron rod. Find the relative permeability of iron?

The resultant magnetic moment of neon atom will be

Assertion (A): The properties of paramagnetic and ferromagnetic substance are not effected by heating.

Reason (R): As temperature rises, the alignment of molecular magnets gradually increases.

Permanent magnet has properties retentivity and coercivity respectively

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 magnet of magnetic moment $M$ is rotated through $360^\circ$ in a magnetic field $H$. The work done will be

An electron in an atom revolves around the nucleus in an orbit of radius 0.5 Å. Calculate the equivalent magnetic moment if the frequency of revolution of the electron is $10^{10}\,\mathrm{MHz}$.

Assertion: Magnetic susceptibility of diamagnetic substance is small negative.
Reason: Diamagnetic substance have unpaired electron.

A magnet of magnetic moment $50\hat i\;A$-${m^2}$ is placed along the $x$-axis in a magnetic field $\vec B = \left( {0.5\;\hat i + 3.0\hat j} \right)T$. The torque acting on the magnet is

Identify the paramagnetic substance:

The relationship between the magnetic susceptibility $(\chi )$ and the magnetic permeability $(\mu)$ is given by:

$(\mu_0$ is the permeability of free space and $\mu_r$ is relative permeability)

Which of the following material is not
ferromagnetic in nature?

Assertion (A): Magnetic moment of an atom is due to both, the orbital motion and spin motion of every electron.

Reason (R): A charged particle at rest produces a magnetic field.

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

At any place on earth, the horizontal component of earth's magnetic field is $\sqrt{3}$ times the vertical component. The angle of dip at that place will be

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 susceptibility of certain magnetic material is 5000 . What is the class of magnetic material?

Lines passing through points of zero declination is

The period of oscillation of a magnet at a place is 2 seconds. When it is remagnetised, so that the pole strength becomes 4 times the initial value. The period of oscillation in second is

For an isotropic medium $B,\;\mu ,\;H$ and $M$ are related as (where $B,\;{\mu _0},\;H$ and $M$ have their usual meanings in the context of magnetic material)

Assertion: Super conductors can be easily levitated in strong magnetic field.
Reason: Magnetic susceptibility of super conductor is extremely positive.

Substances, when placed in a magnetic field
acquire feeble magnetization in the direction
opposite to that of the applied field are called

The needle of a dip circle shows an apparent dip of $45^{\circ}$ in a particular position and $53^{\circ}$ when the circle is rotated through $90^{\circ}$. Find the true dip.

The magnetic susceptibility of a material of a rod is 499. The absolute permeability of vacuum is $4\pi \times {10^{ - 7}}\;\mathrm{H}{\mathrm{m}^{ - 1}}$. The absolute permeability of the material of a rod is

The magnetic moment of a diamagnetic atoms is:

A magnet of distance moment 2 J ${\mathrm{T}^{ - 1}}$ is aligned in the direction of magnetic field of 0.1 T. What is the net work done to bring, the magnet normal to the magnetic field?

The magnetic susceptibility of a paramagnetic material is $1.0 \times 10^{-5}$ at $27^0 \mathrm{C}$ Temperature. Then, at what temperature its magnetic susceptibility would be $1.5 \times 10^{-5}$ ?