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

ELECTRICITY AND MAGNETISM
93
Fig. 156
435. Find the capacitance Co of the battery of identical capacitors
shown in Fig. 154.
436. Each edge of a cube made of wire contains a capacitor
C (Fig. 155). Find the capacitance of this battery if it is connected
to the circuit by means of conductors joined to the opposite
apices A and B of the cube.
437. The spark-capacitor transformer designed by Arkadyev can
be used to obtain short-time high voltages. A diagram of the
device is shown in Fig. 156.
A group of capacitors connected in parallel by conductors AB
and CD having a very high resistance is joined to a high-voltage
SOUTce.
The upper plate of each capacitor is connected through a spark
gap to the lower plate of the following capacitor (gaps 1, 2, 3
and 4). Each following gap is greater than the preceding one.
A discharge occurs when the potential difference between the
plates attains the puncturing voltage of the first gap. After this
the second, third, etc.,
gaps will be punctured, What will the
potential difference be when the last gap is punctured if there
are n capacitors and the voltage applied is Yo?
438. The plates of a charged plane capacitor are alternately
earthed. Will the capacitor be discharged?
439. A plane capacitor is charged to a potential difference U.
Both plates are arranged symmetrically with respect to the earth
so that their potentials relative to it are +U/2 and - U/2,
respectively.
How will the potentials of the plates change relative to the
earth if the first plate is earthed, then disconnected from the
earth, after which the second plate is earthed?
440. One of the plates of a capacitor connected to a battery
with an e.m.I. of