Problem 8. (4 points) A partially filled capacitor. A capacitor is constructed f

Question

Problem 8. (4 points) A partially filled capacitor. A capacitor is constructed from two square, metallic plates of sides 1 and separation d. Charges +O and -O are placed on the plates, and the power supply is then removed. A material of dielectric constant K= 3 is inserted a distance x into the capacitor as shown in Fig. 7. Assume d is much smaller than x If the equivalent capacitance of the partially filled capacitor is two times bigger than the capacitanceK without dielectrics, what is the distance x? (B) 13 Figure 7. A partially filled capacitor

Explanation / Answer

Capacitance of capacotor without dielectric material,

C = e0*l^2 / d

capacitance of capacitor after insertion of dielectric,

C' = (3*e0*l*x / d) + (e0*l*(l-x) / d)

as givrn that,

C' = 2C

2e0*l^2 / d = [(3*e0*l*x / d) + (e0*l*(l-x) / d)]

2l = 3x + (l - x)

2x = l

x = l / 2 (option A)

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---