A long solenoid has 500 turns. When a current of 2 ampere is passed through it, the resulting magnetic flux linked with each turn of the solenoid is 4 $$ \times $$ 10^$$-$$3 Wb. The self-inductance of the solenoid is

A circular disc of radius 0.2 meter is placed in a uniform magnetic field of induction $${1 \over \pi }\left( {{{Wb} \over {{m^2}}}} \right)$$ in such a way that its axis makes an angle of 60^o with $$\overrightarrow B .$$ The magnetic flux linked with the disc is

Two coils of self inductance 2 mH and 8 mH are placed so close together that the effective flux in one coil is completely linked with the other. The mutual inductance between these coils is

As a result of change in the magnetic flux linked to the closed loop as shown in the figure, an e.m.f. $$V$$ volt is induced in the loop. The work done (joule) in taking a charge Q coulomb once along the loop is