Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Problem 7. Repeatall four parts of Problem 6 if the area is increasedto 1 m2, th

ID: 1682246 • Letter: P

Question

Problem 7.Repeatall four parts of Problem 6 if the area is increasedto 1 m2, the plate separationis reduced to

106 m, the space between theplates is filled with a material of dielectric constant 10,000 andthe voltage across

theplates is 1000 V.

Problem8.

A) Carbatteries are sometimes rated in ampere-hours where an ampere is aC/s. What quantity is being

rated?(Is it total charge, total energy, what...?)

B) Whatis the total energy stored in a 12 V, 90 ampere-hour car battery.Compare this energy to energy

stored inthe capacitor of Problem 7.

Explanation / Answer

Area A= 1m^ 2 separation between plates d = 10 ^ -6 m Dielectric constant k = 10000 Voltage across the plates V = 1000 V (A). Ampere - hour = ( C / s) * hour = C i.e., charge (B).voltage V = 12 V charge Q = 90 ampere-hour                = 90 (C / s) * 3600 s                = 324000 C total energy stored E = Q^ 2/ ( 2C )                                 = 52488000000 /C where C = capacitance = kA / d  where = permitivity of free space = 8.85 * 10 ^ -12C ^ 2/ Nm^ 2               = 88500* 10 ^ -6 F               = 0.593 * 10 ^ 12 coulombs