Electricity and Magnetism Answers

The polarisability of a given material is 1.0×10-⁴0 C²mN-¹. Determine it's dielectric constant if the number of molecules in 1 m³ volume of the material is 5.0×10²⅝.

A conductor possesses a positive charge of 3.2x 10^-19 C. How many electron does it have in excess or deficit (e = 1.60 x 10^-19C)
a.2
b.3
c.5
d.6

Using Maxwell’s equations in free space, derive the wave equation for the z-component of
the electric field vector.

The number density of electrons in a metal is 28 3 9.64 10 m− × . What is the drift
velocity of electrons in a wire made up of this metal when a current of 4A flows in
it given that its cross-sectional area is 2.0 mm2
? How long will it take for an
electron to travel a distance of 0.10 m in this wire?

Using Maxwell's equations in free space,derive the wave equationn for the z- component of the electric field vector.

Determine the effective capacitance of the following combination of capacitors given that the capacitance of each capacitor is 3 μF.

A uniform plane wave of 10 kHz travelling in free space strikes a large block of a material having ε=9ε_0,μ=4μ_0 and σ=0 normal to the surface.If the incident magnetic field vector is given by B→=10^(-3) sin(ωt-βy)k^ tesla
Write the complete expression for the incident,reflected and transmitted field vectors.
Please explain in detail.

Using Maxwell’s equations in free space, derive the wave equation for the z-component of
the electric field vector.

Metallic iron contains approximately 1029 atoms per cubic meter. The magnetic moment
of each iron atom is 1.8 × 10−23 Am−1
. If all the dipoles were perfectly aligned what
would be the magnetisation M and the magnetic moment of a bar 10 cm long and 1cm2
in
cross-section?

Three charges q, 2q and q are to be placed on a straight wire of length 10 m.
Determine the positions where the charges should to be placed so that the
electrostatic potential energy of the system is a minimum.