0
a
I
J
R
at
a
0'
Fig. 3.86.
3.297. The system differs from the one examined in the foregoing
problem (Fig. 3.84) by a capacitor of capacitance C replacing the
resistance R. Find the acceleration of the connector.
Fig. 3.84.
Fig. 3.85.
3.298. A wire shaped as a semi-circle of radius a rotates about an
axis 00' with an angular velocity co in a uniform magnetic field of
induction B (Fig. 3.85). The rotation axis is perpendicular to the
field direction. The total resistance of the circuit is equal to R. Neglecting the magnetic field of the induced current, find the mean
amount of thermal power being generated in the loop during a
rotation period.
3.299. A small coil is introduced between the poles of an electromagnet so that its axis coincides with the magnetic field direction.
The cross-sectional area of the coil is equal to S = 3.0 mm2, the
number of turns is N = 60. When the coil turns through 180° about
its diameter, a ballistic galvanometer connected to the coil indicates
a charge q = 4.5 [iC flowing through it. Find the magnetic induction
magnitude between the poles provided the total resistance of the
electric circuit equals R = 40 Q.
3.300. A square wire frame with side a and a straight conductor
carrying a constant current I are located in the same plane (Fig. 3.86).
The inductance and the resistance of the frame are equal to L and R
respectively. The frame was turned through 180° about the axis 00'
separated from the current-carrying conductor by a distance b.
Find the electric charge having flown through the frame.
3.301. A long straight wire carries a current J. At distances a
and b from it there are two other wires, parallel to the former one,
which are interconnected by a resistance R (Fig. 3.87). A connector
a
I
J
R
at
a
0'
Fig. 3.86.
3.297. The system differs from the one examined in the foregoing
problem (Fig. 3.84) by a capacitor of capacitance C replacing the
resistance R. Find the acceleration of the connector.
Fig. 3.84.
Fig. 3.85.
3.298. A wire shaped as a semi-circle of radius a rotates about an
axis 00' with an angular velocity co in a uniform magnetic field of
induction B (Fig. 3.85). The rotation axis is perpendicular to the
field direction. The total resistance of the circuit is equal to R. Neglecting the magnetic field of the induced current, find the mean
amount of thermal power being generated in the loop during a
rotation period.
3.299. A small coil is introduced between the poles of an electromagnet so that its axis coincides with the magnetic field direction.
The cross-sectional area of the coil is equal to S = 3.0 mm2, the
number of turns is N = 60. When the coil turns through 180° about
its diameter, a ballistic galvanometer connected to the coil indicates
a charge q = 4.5 [iC flowing through it. Find the magnetic induction
magnitude between the poles provided the total resistance of the
electric circuit equals R = 40 Q.
3.300. A square wire frame with side a and a straight conductor
carrying a constant current I are located in the same plane (Fig. 3.86).
The inductance and the resistance of the frame are equal to L and R
respectively. The frame was turned through 180° about the axis 00'
separated from the current-carrying conductor by a distance b.
Find the electric charge having flown through the frame.
3.301. A long straight wire carries a current J. At distances a
and b from it there are two other wires, parallel to the former one,
which are interconnected by a resistance R (Fig. 3.87). A connector