Question

You have three parallel plate capacitors, each consisting of two parallel disks of metal separated by a gap filled with some material. Rank the capacitors by their capacitances from highest to lowest, based on the provided plate radii (r), plate separations (d), and filler materials. Dielectric constants for each material can be found in the table to the right. Capacitor 1 (C1):  r = 19.6 mm, d = 11.3 ?m, filled with air. Capacitor 2 (C2):  r = 16.3 mm, d = 19.4 ?m, filled with glass. Capacitor 3 (C3):  r = 6.24 mm, d = 44.7 ?m, filled with Gallium Arsenide (GaAs).

Air=1.00 K

glass=4.50 K

Gallium Arsenide (GaAs)=13.2

rank from highest to lowest

Answer 1

C = Keo A/d

c1 :c2:c3 = 1 * 19.6^2 /11.3 : 4.5 * 16.3^2/19.4 : 13.2 * 6.24^2 /44.7

= 33.996 :61.6129 : 11.498

hence

C2>C1>C3