A capacitor is constructed from two square, metal- lic plates of sides l and separation d. Charges +Q and -Q are placed on the plates, and the power sup- ply is then removed. A material of dielectric constant k is inserted a distance x into the capacitor as shown in Figure P26.78. Assume d is much smaller than x. (a) Find the equivalent capacitance of the device. (b) Calculate the energy stored in the capacitor. (c) Find the direction and magnitude of the force exerted by the plates on the dielectric. (d) Obtain a numerical value for the force when x = €/2, assuming l = 5.00 cm, d = 2.00 mm, the dielectric is glass (K = 4.50), and the capacitor was charged to 2.00 × 10³ V before the dielectric was inserted. Suggestion: The system can be considered as two capacitors connected in parallel. + ++Q

A capacitor is constructed from two square, metal- lic plates of sides l and separation d. Charges +Q and -Q are placed on the plates, and the power sup- ply is then removed. A material of dielectric constant k is inserted a distance x into the capacitor as shown in Figure P26.78. Assume d is much smaller than x. (a) Find the equivalent capacitance of the device. (b) Calculate the energy stored in the capacitor. (c) Find the direction and magnitude of the force exerted by the plates on the dielectric. (d) Obtain a numerical value for the force when x = €/2, assuming l = 5.00 cm, d = 2.00 mm, the dielectric is glass (K = 4.50), and the capacitor was charged to 2.00 × 10³ V before the dielectric was inserted. Suggestion: The system can be considered as two capacitors connected in parallel. + ++Q

Physics for Scientists and Engineers: Foundations and Connections

1st Edition

ISBN:9781133939146

Author:Katz, Debora M.

Publisher:Katz, Debora M.

Chapter27: Capacitors And Batteries

Section: Chapter Questions

Problem 88PQ: A parallel-plate capacitor has square plates of side s = 2.50 cm and plate separation d = 2.50 mm....

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