Name (no name, no credit!) : UFID: Meeting time (circle one): R2 (6454) R3 (3900) R7 (4299) F7 (3903)

Quiz #4 A : – capacitive circuitry – **LOOK** **LOOK**

Allowed info: The SI-prefixes you need are .

Problem: George Lucas designs a Special Edition purely-capacitive circuit1 driven by an E.M.F. of

wherein , , , , and . Question (a) (3 points): Calculate the equivalent capacitance of all capacitors.

Question (b) (4 points): Calculate the energy stored in .

We then calculate:

Problem 2: A parallel-plate capacitor has plates of area separated by , between which is

a dielectric of dielectric-constant . The capacitor will burst into flames if the electric field between the

plates exceeds . Calculate the minimum energy required to set the capacitor on fire.

Due to the uniformity of the field between the capacitor-plates, the maximum electric field corresponds to

a maximum voltage . Meanwhile, the capacitance of two area- parallel (metal) plates with a

material of dielectric constant is due to the plates separating a charge

Correspondingly, this maximum voltage appears in the energy as,

1 In which critics complained that there was far too many things going on at once.