- Two thin plates, suspended in such a way,that they are able to
rotate around vertical axis without friction and other resistance. One
plate made from paramagnetic material, the other from diamagnetic one,
both are in horizontal magnetic field B. Determine the
equilibrium position of the both plates. Find the period of the small
oscillations around equilibrium position for both plates. What is the
ratio of periods for plates, provided they have equal moments of inertia
J and volumes V?
Result:
- Find the value and direction of the electric induction
D and electric field strength E in the
points A , B , C located inside of a homegeneously
polarized disk , whose polariseability P is directed along
thin channel drilled parallel to the axis of the disk. The radius of the
channel is r << d, h (diameter and height) d
>> h .
 Result:
- Find the value and direction of the magnetic induction B
and magnetic field strength H in the points
A , D , C located inside of a homegeneously magnetized
disk , whose magnetic density I is directed along thin
channel drilled parallel to the axis of the disk. The radius of the
channel is r << d, h (diameter and height) . d
>> h .
 Result:
- Using Boltzmann distribution, estimate the ratio of the density of
atoms n near the needle (at the distance d = 400 A
from the edge ) having radius of curvature R = 200 A
to density
 far from the
needle , where electric field could be neglected. The potential of a
needle is =2 kV, the
temperature T = 300 K . Permittivity of the atom is of the
order of its volume  . .
Result:
- In vertically oriented microwave guide with an ideally conducting
walls is being excited Å -wave (TM - wave)
having frequency slightly above the critical one. Along the waveguide
axis a small dielectric ball having radius R and
dielectric constant
 is suspended
on the thin wire of a length. l . Define the period of the
harmonic oscillations Ò of the ball in the plane Å ,
ê , if the intensity of the microwave is  .
Direction:
permittivity of dielectric ball in electric field Å is
given by Klausius - Mosotti formula: 
Result
- Dielectric capacity of the distance between plates 10 ñì is being
periodically recharged by current of 1 à with frequency 50 hertz. How
many photons are in vortex electrical field induced by alternating
magnetic field excited by displacement current ?
Result:
3 photons.
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