Fig. 75(^74) Aptitude Test Problems in Physics
3.3. Determine the strength E of the electric
field at the centre of a hemisphere produced
by charges uniformly distributed with a
density a over the surface of this hemisphere.
3.4. The strength of the electric field pro-
duced by charges uniformly distributed over
the surface of a hemisphere at its centre 0
is E 0. A part of the surface is isolated from
this hemisphere by two planes passing
through the same diameter and forming
an angle cc with each other (Fig. 75).
Determine the electric field strength E
produced at the same point 0 by the charges
located on the isolated surface (on the
"mericarp").
3.5*. Two parallel-plate capacitors are ar-
ranged perpendicular to the common axis.
The separation d between the capacitors is
much larger than the separation 1 between
their plates and than their size. The capac-
itors are charged to ql and q 2 respectively
(Fig. 76).
Find the force F of interaction between
the capacitors.
3.6. Determine the force F of interaction
between two hemispheres of radius R touch-