Electricity and Magnetism Answers

A force of 0.037 N is required to move a charge of 35.9 µC a distance of 24 cm in an electric field. What is the size of the potential difference between the two points?

A metal ball has - 8 Coulomb of charge. If it receives 0.50*10^20 number of electrons, what will be the resultant charge of the ball?

Derive the wave equation for the z-component of the electric field of an electromagnetic

wave and show that the wave propagates in free space with the speed of light .

Why do magnetic moments in ferromagnetic materials, tend to align parallel to each other?

Establish the relation B = μ0(H + M), for a ferromagnetic material.

A particle carrying charge q enters a magnetic field B with velocity v at an angle

Θ≠0≠90° . Show that it follows a helical path. Determine the radius of the helix.

A copper wire of diameter 1 mm and length 30 m is connected across a battery of 2V.

Calculate the current density in the wire and drift velocity of the electrons. The resistivity

of copper is 1.72 ×10^–8Ωm and n = 8.0 ×10^28 electrons m^–3.

.

A glass of relative permitivity 4 is kept in an external electric field of magnitude 10^2 Vm^–1

.

Calculate the polarisation vector, molecular/atomic polarisability and the refractive index

of the glass

The capacitance of a parallel plate capacitor is increased by a factor of 7 when a dielectric

material fills the space between its plates. What is the relative permitivity of the dielectric

material? If this material is placed in between the plates of a cylindrical capacitor of outer

and inner radii 12 cm and 10 cm, respectively, calculate the capacitance per unit length of

the cylindrical capacitor.

State, giving reasons, whether the following statements are True or False:

(1)The electric field associated with a plane electromagnetic wave is given by

E = 50 cos (ωt – 10πx) zˆ Vm^–1

. Its wavelength is 0.5 m.

State, giving reasons, whether the following statements are True or False:

(1)Step-up transformer converts high voltage, low current into low voltage high current.