[amp_mcq option1=”is minimum at the resonant frequency” option2=”always increases as the applied frequency increases” option3=”always decreases as the applied frequency increases” option4=”is maximum at the resonant frequency E. None of the above” correct=”option1″]
The correct answer is: A. is minimum at the resonant frequency.
The impedance of a series RLC circuit is given by the following equation:
$Z = \sqrt{R^2 + (X_L – X_C)^2}$
where $R$ is the resistance, $X_L$ is the inductive reactance, and $X_C$ is the capacitive reactance.
The inductive reactance is given by the following equation:
$X_L = 2\pi f L$
where $f$ is the frequency and $L$ is the inductance.
The capacitive reactance is given by the following equation:
$X_C = \frac{1}{2\pi f C}$
where $f$ is the frequency and $C$ is the capacitance.
At the resonant frequency, the inductive reactance and the capacitive reactance are equal in magnitude but opposite in sign. This means that they cancel each other out, and the impedance of the circuit is equal to the resistance.
Therefore, the total impedance of a series RLC circuit is minimum at the resonant frequency.
Option B is incorrect because the impedance of a series RLC circuit does not always increase as the applied frequency increases. In fact, the impedance of a series RLC circuit is minimum at the resonant frequency, and it increases or decreases as the frequency moves away from the resonant frequency.
Option C is incorrect because the impedance of a series RLC circuit does not always decrease as the applied frequency increases. In fact, the impedance of a series RLC circuit is minimum at the resonant frequency, and it increases or decreases as the frequency moves away from the resonant frequency.
Option D is incorrect because the total impedance of a series RLC circuit is minimum at the resonant frequency, not maximum.
Option E is incorrect because the total impedance of a series RLC circuit is minimum at the resonant frequency.