Magnetism and M...

Potential energy of a bar magnet of magnetic moment $$M$$ placed in a magnetic field of induction $$B$$ Such that it makes an angle $$\theta$$ with the direction of $$B$$ is (take $$\theta={90}^{o}$$ as datum)

Figure shows a square loop of side $$1m$$ and resistance $$1\Omega$$. The magnetic field on left side of line PQ has a magnitude $$B=1.0T$$. The work done in pulling the loop out of the field uniformly in $$1s$$ is

A circular loop of area $$1$$ $$cm^2$$, carrying a current of $$10$$A, is placed in a magnetic field of $$0.1$$T perpendicular to the plane of the loop. The torque on the loop due to the magnetic field is?

A bar magnet is made to fall through a vertical copper tube. The speed ($$v$$) of the magnet as a function of time ($$t$$) is best represented by

The figure shows the various positions (labelled by subscripts) of small magnetised needles P and Q. The arrows show the direction of their magnetic movement.configuration corresponds to the lowest potential energy among all the configurations shown 

A conductor behave as a super conductor

A short-circuited coil is placed in a time-varying magnetic field. Electrical power is dissipated due to the current induced in the coil. If the number of turns were to be quadrupled and the wire radius halved, the electrical power dissipated would be:

A long straight wire of circular cross-section is made of a non-magnetic material. The wire is of radius $$a$$.The wire carries a current $$I$$ which is uniformly distributed over its cross-section. The energy stored per unit length in the magnetic field contained within the wire is

Two protons enter a region of the transverse magnetic field. What will be the ratio of the time period of revolution if the ratio of energy is $$2\sqrt 2 :\sqrt 3 ?$$ 

When two co axis coil having same current in same direction are brought close to each other then the value of current in both coils: