Question

The minimum capacitance of a variable capacitor in a radio is 4.18 pF. (a) What is the inductance of a coil connected to this capacitor if the oscillation frequency of the L-C circuit is 1600 times 103 Hz, corresponding to one end of the AM radio broadcast band, when the capacitor is set to its minimum capacitance? (b) The frequency at the other end of the broadcast band is 540 times 103 HZ. What is the maximum capacitance of the capacitor if the oscillation frequency is adjustable over the range of the broadcast band?

Can you please show an image that shows what is happening with images

Answer 1

(a) Inductance is found from resonant frequency formul w^@ = (2pif) ^2 = 1/Lc arrowdblright L = 1/(2pif) ^2 times c = 1/(2 times 3.14 times 1600 times 10^3) ^2 times(4.18 times 10^-12F) = 2.3695 times 10^-3 H = 2.37 times 10^-3 (b) capacitance c = 1/(2pif) ^2 L = 1/(2 times3.14 times 540 times 10^3) 2 times(2.37 times 10^-3) = 3.668 times 10^-11 = 3.7 times 10^-11 F