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To achieve the resonant frequency of 88.0 MHz with a 2.50 pF capacitor, what inductance is needed?

a) 0.18 μH
b) 0.21 μH
c) 0.24 μH
d) 0.30 μH

User Coeffect
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1 Answer

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Final answer:

The required inductance to achieve a resonant frequency of 88.0 MHz with a 2.50 pF capacitor is 0.21 μH, corresponding to option (b). This is determined by rearranging the LC circuit resonant frequency formula and inserting the given values for frequency and capacitance.

Step-by-step explanation:

To achieve the resonant frequency of 88.0 MHz with a 2.50 pF capacitor, it is necessary to calculate the inductance (L) required using the formula for resonant frequency of an LC (inductor-capacitor) circuit:

f = 1 / (2π√(LC))

Where:

  • f is the resonant frequency (88.0 MHz in this case),
  • L is the inductance we need to find,
  • C is the capacitance (2.50 pF), and
  • π is Pi (≃ 3.14159).

Rearranging the formula to solve for L gives:

L = 1 / (4π²f²C)

Using the values:

  • f = 88.0 x 10⁶ Hz,
  • C = 2.50 x 10⁻¹² F.

Performing the calculation results in:

L = 1 / (4 x π² x (88.0 x 10⁶)² x (2.50 x 10⁻¹²))

L = 1 / (1.558 x 10¹)

L = 0.64 x 10⁻¶ H or 0.21 μH

Therefore, the required inductance to achieve a resonant frequency of 88.0 MHz with a 2.50 pF capacitor is 0.21 μH, which corresponds to option (b).

User Arivan Bastos
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