Magnetism and M...

A bar magnet of magnetic moment $$M$$ is divided into '$$n$$' equal parts by cutting parallel to length. Then one part is suspended in a uniform magnetic field of strength $$2T$$ and held making an angle $$60^{0}$$ with the direction of the field. When the magnet is released, the kinetic energy of the magnet in the equilibrium position is:

Assertion : Lenz's Law violates the principle of conservation of energy
Reason : Induced emf always opposes the change in magnetic flux responsible for its production.

The least value of magnetic moment (where $$m$$ is the mass of the electron, $$e$$ is the charge of electron) is :

The given figure shows planar loops of different shapes moving out of or into a region of a magnetic field, which is directed normal to the plane of the loop away from the reader. Then the direction of induced current in each loop using Lenz's law will be 

Direction of current in the loop at $$t=\dfrac{\pi}{3 \omega}$$ :

Two coils carrying current in opposite direction are placed co-axially with centres at some finite separation. If they are brought close to each other then current flowing in them should

A small circular loop is suspended from a insulating thread. Another co-axial circular loop carrying a current $$I$$ and having radius much larger than the first loop starts moving towards the smaller loop. The smaller loop will :

The ring $$B$$ is coaxial with a solenoid $$A$$ as shown in figure. As the switch $$S$$ is closed at $$t=0$$, the ring $$B$$

In the graphs below, the resistance R of a superconductor is shown as a function of its temperature T for two different magnetic fields $$B_1$$ (solid line) and $$B_2$$ (dashed line). If $$B_2$$ is larger than $$B_1$$, which of the following graphs shows the correct variation of R and T in these fields?

Two identical conductors $$P$$ and $$Q$$ are placed on two frictionless rails $$R$$ and $$S$$ in a uniform magnetic field directed into the plane. If $$P$$ is moved in the direction shown in figure with a constant speed, then rod $$Q$$.