Bukhovtsev-et-al-Problems-in-Elementary-Physics

116 PROBLEMS
tic field in the direction of side a with a velocity e. The intensity
of the magnetic field H is perpendicular to the base of
the block with the sides a and c (Fig. 199). .
Determine the intensity of the electric field in the block and
the density of the electric charges on the surfaces of the parallelepiped
formed by sides a and b.
567. An uncharged metal cylinder with a radius r revolves about
its axis in a magnetic field with an angular velocity ro. The
intensity of the magnetic field is directed along the axis of the
cylinder.
What should the intensity of the magnetic field be for no
electrostatic field to appear in the cylinder?
3-5. Electromagnetic Induction. Alternating
Current
568. Determine the direction of the intensity of an electric
field in a turn placed in a magnetic field (Fig. 200) directed away
from us in a direction perpendicular to the plane of the turn.
The intensity of the magnetic field grows with time.
569. A rectangular circuit ABeD moves translationally in the
magnetic field of a current flowing along straight long conductor
00' (Fig. 201). Find the direction of the current induced in the
circuit if the turn moves away from the conductor.
570. A non-magnetized iron rod flies through a coil connected
to a battery and an ammeter (Fig. 202). Draw an approximate
diagram of the change of current in the coil with time as the
rod flies through it.
571. A current in a coil grows directly with time. What is the
nature of the relation between the current and time in another
coil inductively connected to the first one?
0'
B..---.O
o
+
A 0
Fig. 200
a
Fig. 201 Fig. 202