The variable capacitance of a radio tuner consists of six plates connected together placed alternately between six other plates, also connected together (Fig. 22-21). Each plate is separated from its neighbour by 1.1 mm of air. One set of plates can move so that the area of overlap varies from 1.0 cm2 to 9.0 cm2.
(a) Are these capacitors connected in series or in parallel?
(b) Determine the range of capacitance values.
(c) What value of inductor id needed if the radio is to tune AM stations from 550 kHz to 1600 kHz?