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

Answer:

The value of variable capacitor is $1.89 \times 10^{-13}$ F

Explanation:

Given :

Inductance $L = 250 \times 10^{-3}$ H

Frequency $f = 731 \times 10^{3}$ Hz

According to the cutoff frequency,

   $f = \frac{1}{2\pi \sqrt{LC} }$

Now we find the value of capacitance,

  $C = \frac{1}{4\pi ^{2} f^{2} L }$

  $C = \frac{1}{4\times 9.85 \times (731 \times 10^{3} )^{2} \times 250 \times 10^{-3} }$

  $C = 1.89 \times 10^{-13}$ F

Therefore, the value of variable capacitor is $1.89 \times 10^{-13}$ F