Electricity and Magnetism Answers

Using Maxwell’s equations in free space, derive the wave equation for the
electric field vector. Obtain the conditions under which the following time varying
electric and magnetic fields satisfy Maxwell’s equations in vacuum with no source
charges or currents:
sin ( )
ˆ
0 E = k E y − vt
) sin (
ˆ
0 B = i B y − vt
where E0 and B0 are constant

A non-relativistic free electron has kinetic energy K. If its wavelength λ triples, it is kinetic energy is:

A wheel having mass m has charge +q and -q on diametrically opposite points. It remains in equilibrium on a rough inclined plane in the presence of vertical electric field E. The value of E is__.
Ans: mg/2q

A α-particle moves in a circle of radius 5.0*10^-2m in magnetic field of 2.0T. Find the speed of the α-particle.

The electrical field associated with a monochromatic beam becomes zero 1.2× 1000000000000000 times per second . Find the maximum kinetic energy of the photoelectrons when this light falls on a metal surface whose work function is 2.0ev (1) 0.24ev (2) 0.48 ev (3) 0.72 ev. (4) 0.96 ev

A positive 20mC charge is placed at the centre of a circle of radius 20 cm. If we move a positive 2mC charge once along the circumference of the circle, will any work be done in the process? Justify your answer.

The electric potential near an isolated positive charge is a) positive or b) negative

You have a 1.0-m-long copper wire. You want to make an
N-turn current loop that generates a 1.0 mT magnetic field at the
center when the current is 1.0 A. You must use the entire wire.
'What will be the diameter of your coil?

Find magnetic field outside the super conductor. Show that the normal component of magnetic field is continuos across the superconductor. Find H outside the superconductor. Find W outside the superconductor so that H=-GRAD W