Question A8.10: The frequency of resonance, f, of a tuned circuit (see Fig. ...

The frequency of resonance, f, of a tuned circuit (see Fig. A8.4) is given by the relationship:

f=\frac{1}{2 \pi \sqrt{L C}}

If a tuned circuit is to be resonant at 6.25 MHz and C = 100 pF, determine the value of inductance, L .

74
The blue check mark means that this solution has been answered and checked by an expert. This guarantees that the final answer is accurate.
Learn more on how we answer questions.

Here we know that:
C = 100 pF = 100 × 10^{-12} F
f = 6.25 MHz = 6.25 × 10^{6} Hz
π = 3.142 (use the ‘π’ button on your calculator!)
L = ?
First we will re-arrange the formula in order to make L the subject:

f=\frac{1}{2 \pi \sqrt{L C}}

Squaring both sides gives:

f^{2}=\left(\frac{1}{2 \pi \sqrt{L C}}\right)^{2}=\frac{1^{2}}{2^{2} \pi^{2}(\sqrt{L C})^{2}}=\frac{1}{4 \pi^{2} L C}

Re-arranging gives:

L=\frac{1}{4 \pi^{2} f^{2} C}

We can now replace f, C and π by the values that we know:

L=\frac{1}{4 \times 3.142^{2} \times\left(6.25 \times 10^{6}\right)^{2} \times 100 \times 10^{-12}} H

 

\begin{aligned}L &=\frac{1}{39.49 \times 39.06 \times 10^{12} \times 100 \times 10^{-12}} H \\&=\frac{1}{154,248}=\frac{1}{1.54248 \times 10^{5}}=\frac{1}{1.54248} \times 10^{-5} \\ &=0.648 \times 10^{-5}=6.48 \times 10^{-6} H = 6 . 8 \mu H \end{aligned}

 

Related Answered Questions

Question: A8.17

Verified Answer:

Now power gain expressed in decibels will be given...
Question: A8.16

Verified Answer:

In Bels, power gain =\log _{10}(27,...
Question: A8.12

Verified Answer:

The data have been shown plotted in Fig. A8.10. No...
Question: A8.11

Verified Answer:

Here we know that: R = 25 Ω Z = 50 Ω X = ? First w...