. A capacitor is made from two 1.1-cm-diameter coins separated by a distance 0.1

Question

. A capacitor is made from two 1.1-cm-diameter coins separated by a distance 0.10-mm, air is nthe two coi s. A 12-V battery is connected to the capacitor until the capacitor is fully charged. The battery is then removed and the charge on each coin is maintained. A) How much charge is on each coin? (3') B) How much energy is stored in this capacitor? (3') C) If the two coins are moved to 0.20-mm away from each other, while maintaining the charge on both coins, how much energy is stored in the capacitor now? (2') D) How could separating the coins change energy? (2")

Explanation / Answer

C = e0 A / d

C = (8.854 x 10^-12) (pi (0.011/2)^2 ) / (0.1 x 10^-3)

C = 8.414 x 10^-12 F

(A) Q = C V = 101 x 10^-12 C Or 101 pC

(B) U = C V^2 /2 = 605.8 x 10^-12 J

(C) U = Q^2 /2 C

Q -> constant

C' = C/2

U' = 2U = 1212 x 10^-12 J

(D) Work done to increase the distance will stored into capacitor.

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.