Electricity and Magnetism Answers

Using Maxwell’s equations in vacuum, derive the wave equation for the z-component

of the electric field vector associated with an electromagnetic wave.

What rate of change of current in a solenoid having self-inductance 19.4 mH produces a self-induced emf of 100 mV in it?

A long, straight wire of diameter 5.0 mm carries a uniformly distributed current of

15 A. At what distance from the axis of the wire will the magnitude of B be maximum? Justify your answer.

A wire loop of resistance

10 ohm and radius 10 cm is kept in the plane of this paper in a uniform magnetic field B.

The direction of B is perpendicular to the

plane of the page and points out of it and its magnitude is increasing at the rate of 0.50T/s.

Determine the magnitude and direction of the induced current in the loop.

Calculate the magnitudes of magnetic intensity

H and the magnetic field B at the centre of a 1500-turn solenoid which is 0.22 m long and carries a current of

1.5 A.

A long, straight wire of diameter 5.0 mm carries a uniformly distributed current of

15 A. At what distance from the axis of the wire will the magnitude of

B



be

maximum? Justify your answer

A 0.5 m length of current-carrying wire kept perpendicular to a magnetic field of

magnitude 200 mT experiences a force of 1.5 mN. What is the current flowing in the

wire.

A dielectric of dielectric constant 2.5 is filled in the gap between the plates of a

capacitor. Calculate the factor by which the capacitance is increased, if the

dielectric is only sufficient to fill up one-fourth of the gap

Define electric displacement vector

D


and deduce Gauss’s law for dielectrics

The electric potential at a point is given by

V = z(z² - 4x²). Calculate the electric field

E at that point