Magnetism and matter practice · Mixed difficulty

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 (A): Magnetic poles are only mathematical assumptions having no real existence.

Reason (R): A charged particle is moved along a magnetic field line. The magnetic force on the particle is perpendicular to its velocity.

A small bar magnet of moment $M$ is placed in a uniform field $H$. If magnet makes an angle of $30^\circ$ with field, the torque acting on the magnet is

For a paramagnetic material, the dependence of the magnetic susceptibility $X$ on the absolute temperature is given as

A magnet is dropped down in infinitely long vertical
copper tube.

A dip circle shows an apparent dip of $45^\circ$ at a place where the true dip is $30^\circ$. If the dip circle is rotated through $90^\circ$, what apparent dip will it show:

Electromagnets are made of soft iron because soft iron has

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

Nickel shows ferromagnetic property at room temperature. If the temperature is increased beyond Curie temperature, then it will show

The radius of the coil of a tangent galvanometer which has 10 turns is 0.1 m. The current required to produce a deflection of $60^\circ \;\left( {{B_H} = 4 \times {{10}^{ - 5}}\mathrm{\;T}} \right)$ is

When the N- pole of a bar magnet points
towards the south and S- pole towards the
north, the null point are at the

If a diamagnetic substance is brought near north or south pole of a bar magnet, it is

The magnetic field due to a small magnetic dipole of magnetic moment $M$, at distance $r$ from the centre on the equatorial line is given by (in M.K.S system)

The effective length of a magnet is 31.4 cm and its pole strength is 0.5 Am. Calculate its magnetic moment. If it is bent in form of semicircle, then magnetic moment will be

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

A magnet hung at $45^{\circ}$ with magnetic meridian makes an angle of $60^{\circ}$ with the horizontal. The actual value of the angle of dip is

The intensity of magnetic field due to an isolated pole of strength $m$ at a point distance $r$ from it will be

A short bar magnet experiences a torque of magnitude 0.64 J. When it is placed in a uniform magnetic field of 0.32 T, taking an angle of  with the direction of the field. The magnetic moment of the magnet is

A magnetised wire is bent into an arc of a circle subtending an angle $60^\circ$ at its centre. Then its magnetic moment is X. If the same wire is bent into an arc of a circle subtending an angle $90^\circ$ at its centre then its magnetic moment will be

Which of the following properties is 'False' for
a bar magnet ?

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

A magnetic dipole is placed in two perpendicular magnetic fields ${\mathrm{\vec B}}$ and ${\mathrm{\vec H}}$ and is in equilibrium taking angle $\mathrm{\theta }$ with ${\mathrm{\vec B}}$. Then

The effect due to uniform magnetic field on a freely suspended magnetic needle is as follows

Relative permittivity and permeability of a material are ${\mathrm{\varepsilon }_r}$ and ${\mathrm{\mu }_r},$ respectively. Which of the following values of these quantities are allowed for a diamagnetic material?

Magnetic intensity for an axial point due to a short bar magnet of magnetic moment $M$ is given by

The time period of a bar magnet suspended horizontally in the earth’s magnetic field and allowed to oscillate

A magnetic dipole is placed in a uniform magnetic field. The net magnetic force on the dipole

Curie-Weiss law is obeyed by iron

A magnetic needle is kept in a non-uniform magnetic field. It experiences force and torque both due to unequal forces acting on poles.

Keeping dissimilar poles of two magnets of equal pole strength and length same side, their time period will be