Question

The inductor in the RLC tuning circuit of an AM radio has a value of 250 mHmH . You may want to review (Pages 857 - 860) . Part A What should be the value of the variable capacitor in the circuit to tune the radio to 731 kHz kHz

Answer 1

The value of variable capacitor is
`1.89 * 10^(-13)` F

Step-by-step explanation:

Given :

Inductance
`L = 250 * 10^(-3)` H

Frequency
`f = 731 * 10^(3)` Hz

According to the cutoff frequency,

`f = (1)/(2\pi √(LC) )`

Now we find the value of capacitance,

`C = (1)/(4\pi ^(2) f^(2) L )`

`C = (1)/(4* 9.85 * (731 * 10^(3) )^(2) * 250 * 10^(-3) )`

`C = 1.89 * 10^(-13)` F

Therefore, the value of variable capacitor is
`1.89 * 10^(-13)` F