Magnetism and M...

Which of the following is not true about the advantages of electromagnet over permanent magnet?

In the given diagrams, compasses are used to plot the magnetic field around a bar magnetic field around a bar magnet with poles marked N (North) and S (South). Which of the following diagrams correctly shows the expected field pattern?

A square loop of wire, side length 10 cm is placed at angle of $$45^{o}$$ with a magnetic field that changes uniformly from 0.1 T to zero in 0.7 seconds. The induced current in the loop ( its resistance is $$1\Omega$$) is

Potential energy of a bar magnet, of magnetic moment M is placed in a magnetic filed of induction B such that it makes an angle $$\theta$$ with the direction of B is? 

Which of the following statement is correct?

A copper rod of length $$l$$ rotates about its end with angular velocity $$\omega$$ in a uniform magnetic field B. The emf developed between the ends of the rod if the field is normal to the plane of rotation is:

What is the phenomenon shown by ferromagnetic substances whereby the magnetic flux through the medium on magnetising field as well as previous state of the substance?

The direction of an induced electromotive force is always such as to oppose the cause that produces it. This is called :

Dynamo is a device that converts.

 Charged particle (charge$$=q$$; mass$$=m$$) is rotating in a circle of radius $$R$$ with uniform speed $$V$$, Ratio of its magnetic moment ($$\mu$$) to the angular momentum ($$L$$) is