Magnetic Properties of Matter

The mid points of two small magnetic dipoles of length $d$ in end-on positions, are separated by a distance $x$$\left(x\gg\,d\right)$. The magnitude of force between them is proportional to $x^{-n}$ where $n$ is :

A fighter plane of length 20 m, wing span (distance from tip of one wing to the tip of the other wing) of 15 m and height 5 m is flying towards east over Delhi. Its speed is $240ms^{-1}.$ The earth's magnetic field over…

A short bar magnet is placed in the magnetic meridian of the earth with North Pole pointing north. Neutral points are found at a distance of $30\mathrm{cm}$from the magnet on the East-West line, drawn through the middle…

A perfectly diamagnetic sphere has a small spherical cavity at its centre, which is filled with a paramagnetic substance. The whole system is placed in a uniform magnetic field $\vec{B}$. Then the field inside the…

The magnetic field of earth at the equator is approximately $4\times\,10^{-5}\text{T}$.The radius of earth is $\text{6.4}\times\,10^{6}\text{m}$. Then the dipole moment of the earth will be nearly of the order of :

Following plots show Magnetization $(M)$ vs Magnetising field $(H)$ and Magnetic susceptibility $(\chi\,)$ vs Temperature $(T)$ graph : Which of the following combination will be represented by a diamagnetic material?

At some location the horizontal component of earth's magnetic field is $18\times\,10^{-6}T.$ At this location, magnetic needle of length $0.12m$ and pole strength $1.8\mathrm{Am}$ is suspended from its mid-point using a…

Two short bar magnets of length $1\operatorname{cm}\,$ each have magnetic moments $1\operatorname{.20}\,Am^{2}$ and $1\operatorname{.00}\,Am^{2}$ respectively. They are placed on a horizontal table parallel to each…

A $25\mathrm{cm}$ long solenoid has the radius $2\mathrm{cm}$ and $500$turns. It carries a current of $15A$. If it is equivalent to a magnet of the same size and magnetization…

At a certain place the angle of dip is $30^{\circ}$ and the horizontal component of earth's magnetic field is $0.5G$. The earth's total magnetic field (in $G$), at that certain place, is

The vertical component of the earth's magnetic field is $6\times\,10^{-5}T$ at any place where the angle of dip is $37^{\circ}$. The earth's resultant magnetic field at that place will be (Given…

A ceiling fan having $3$ blades of length $80\mathrm{cm}$ each is rotating with an angular velocity of $1200\mathrm{rpm}$. The magnetic field of earth in that region is $0.5G$ and angle of dip is $30^{\circ}$. The emf…