Electromagnetic...

The magnetic flux through a circuit of resistance 'R' changes by an amount $$\Delta \Phi$$ at a time $$\Delta t$$. Then the total quantity of electric charge Q that passes any point in the circuit during the time $$\Delta t $$ is represented by 

When a rectangular coil is rotated in a uniform magnetic field about an axis passing through its centre and perpendicular to the field, the induced emf in the coil is maximum when the plane of the coil is

A wire 88 cm long bent into a circular loop is placed perpendicular to the magnetic field of flux density 2.5 Wb $$m^{-2}$$. Within 0.5 s, the loop is changed into a square and flux density is increased to 3.0 Wb $$m^{-2}$$. The value of e.m.f. induced is :

A copper ring is moved towards the north pole of a bar magnet. Then

A metal ring with a cut as shown in the figure is held horizontally and a bar magnet is dropped though the ring, then the acceleration of the magnet is ________.

Faraday's second law of electromagnetic induction states that:

The current flowing through the primary coil of mutual inductance 8 H is reduced to zero in $$10^{-3}$$s. As a result of which a $$24\times 10^3$$ V is induced in the secondary. The initial current through the primary is _____A. 

What will be the magnitude of e.m.f. induced in a 200 turns coil with cross section area 0.16 $$m^2$$ if the magnetic field through the coil changes from 0.10 Wb $$m^{-2}$$ to 0.30 $$m^{-2}$$ in 0.05 second.

The variation of anode current in a triode valve corresponding to a change in grid potential at three different values of the plate potential is shown in the given figure. The mutual conductance of triode is