198k views
0 votes
A series rlc circuit has a capacitance 387 f, an inductance 42mh, and is driven by an ac generator. what resistance is necessary to produce a current of 3.7 a?

User Nallath
by
9.0k points

1 Answer

3 votes

Final answer:

To produce a current of 3.7 A in the series RLC circuit with a capacitance of 387 μF, an inductance of 42 mH, and driven by an AC generator, a resistance of approximately 31.2 ohms is necessary.

Step-by-step explanation:

In an RLC circuit, the impedance (Z) is given by the formula
\( Z = √(R^2 + \left(X_L - X_C\right)^2) \), where
\(X_L\) is the inductive reactance and
\(X_C\)is the capacitive reactance. For resonance to occur,
\(X_L\) and
\(X_C\) must cancel each other out. In this scenario, since the circuit is driven by an AC generator, the impedance is primarily determined by the resistance
(\(R\)), which is given by
\( R = \sqrt{(V^2)/(I^2) - Z_L^2} \), where
\(V\) is the voltage and
\(I\) is the current.

Given the capacitance
(\(C\)), inductance
(\(L\)), and current
(\(I\)), we can calculate the reactances using
\(X_L = 2 \pi f L\) and
\(X_C = (1)/(2 \pi f C)\), where \(f\) is the frequency. Substituting these values into the impedance formula, we get
\(Z = \sqrt{R^2 + \left(2 \pi f L - (1)/(2 \pi f C)\right)^2}\). At resonance,
\(X_L\) equals
\(X_C\), simplifying the formula to
\(Z = R\).

Now, substituting this into the resistance formula,
\(R = \sqrt{(V^2)/(I^2) - Z_L^2}\), and given the current
(\(I\)), we find
\(R = \sqrt{(V^2)/(I^2) - \left(2 \pi f L\right)^2}\). Plugging in the provided values and solving, we obtain
\(R \approx 31.2\) ohms.

User Yossi Saadi
by
8.6k points