Electromagnetic...

Who gave the principle of Electro-magnetic induction?

The equivalent quantity of mass in electricity is :

Mutual inductance of two coils can be increased by 

The self inductance of two solenoids A & B having equal length are same. If the number of turns in two solenoids A & B are $$100$$ and $$200$$ respectively. The ratio of radii of their cross-section will be __________.

A 60 volt - 10 watt bulb is operated at 100 volt - 60 Hz a.c. The inductance required is?

A magnetic flux of 5 microweber is linked with a coil when a current of 1 mA flows through it. Calculate self-inductance of the coil.

A source of 220 V is applied in an A C circuit . The value of resistance is 220 $$\Omega$$. Frequency & inductance are 50Hz & 0.7 H then wattless current is 

A small square loop of wire of side $$l$$ is placed inside a large square loop of wire of side $$L(L>>l)$$.
The loops are co-planar and their centres coincide. The mutual inductance of the system is proportional to:

A flat coil of 500 turns, each of area $$50cm^2$$, rotates in a uniform magnetic field of $$0.14 Wb/m^2$$ about an axis normal to the field at an angular speed of $$150 rad/s$$. The coil has a resistance of $$5\Omega$$. The induced e.m.f. is applied to an external resistance of $$10\Omega$$, The peak current through the resistance is:

A circular coil of radius $$8$$cm and $$20$$ turns rotates about its vertical diameter with an angular speed of 50 rad $$s^{-1}$$ in a uniform horizontal magnetic field of $$8\times 10^{-2}T.$$ The maximum emf induced in the coil is nearly