A pyrex filled parallel plate capacitor has plates of area 0.406 m2 and a separa

Question

A pyrex filled parallel plate capacitor has plates of area 0.406 m2 and a separation of 2.5 times 10-5 m. The dielectric constant for pyrex is 4.6 and the dielectric strength is 1.4 times 107 V/m. a) if the capacitor is connected to a 30 v battery how much energy is stored in the capacitor? B) Would the energy in the capacitor increase, decrease or stay the same if the pyrex is removed but the 30 volt battery is still connected? explain. c) if the capacitor was disconnected from the battery and then the pyrex was removed, would the energy stored bigger, smaller or equal to the energy stored in part A? Explain.

Explanation / Answer

A)

here, the capacitance of the capacitor is

C = 4.6 * 8.854 *10^-12 * 0.406/2.5 *10^-6

C = 6.614 *10^-6 F

Now,

energy stored in the capacitor is

U = 0.5 * 6.614 *10^-6 * 30^2

U = 2.976 *10^-3 J

the energy stored in the capacitor is 2.976 *10^-3 J

B)

if the pyrex is removed as the capacitance decreses and Voltage stays the same ,

the energy stored in the capacitor decreases .

C)

if the battery is removed before,

charge Q stays the same ,

as energy stored = 0.5 Q^2/C

as C decreases , U will increase ,

the energy stored will increase

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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