Problem 58-1    Source:  Problem elaborated by the author of the site.

Calculate at what frequency the circuit shown in the Figure 58-1.1 will have the lowest voltage value at the terminals a-b. Make a chart showing the values in around the rejection frequency.

Problem 58-2    Source:   Problem elaborated by the author of the site.

We wish to use an LC parallel circuit, show in the Figure 58-2.1, to tune the frequencies corresponding to the AM range, which ranges from 530 KHz to 1 600 KHz. Using an inductor of 100 µH calculate the value of a variable capacitor, which associated in parallel with a fixed value, provides the AM band tuning.

Problem 58-3    Source:   Example 20.5 - pag.e 614 - BOYLESTAD, Robert L. - Book: Introdução à Análise de Circuitos - 10ª ed. - 2008.

A series RLC circuit is designed to resonate at ω_S = 10⁵ rad/s, with a bandwidth of 0.15 ω_S, and consumes 16 watts from a source of 120 volts in the resonance.

a) Determine the value of R.

b) Calculate the bandwidth in hertz.

c) Calculate the nominal values of L and C.

d) Which is Q_S of circuit.

e) Determine the relative bandwidth.

Problem 58-4    Source:   Example 13.6 - page 343 - BARTKOWIAK, Robert A. - Book: Circuitos Elétricos - 2ª ed. - Editora Makron Books - 1999.

A series resonant circuit has a resonance frequency of 10 KHz. If Q = 100, what are the cut-off frequencies?

Problem 58-5    Source:   problem 6 - page 355 - BARTKOWIAK, Robert A. - Book: Circuitos Elétricos - 2ª ed. - Editora Makron Books - 1999.

The antenna circuit of a radio receiver consists of a serial connection of a coil of 10 mH, a variable capacitor, and a 50 ohm resistor. A signal of 880 KHz produces a potential difference of 100 µV on the resonance. Find:

a) The current in the resonance.

b) The value of capacitance at resonance.

c) Determine the Q of the antenna circuit.

Problem 58-6    Source:   Example 14.5 - page 317 - HUGGES, A. E. - Book: Electrical and Eletronic Technology - 10ª ed. - Editora Pearson - 2008.

A coil of 1 kΩ resistance and 0.15 H inductance is connected in parallel with a variable capacitor across a 2.0 V, 10 kHz a.c. supply as shown in Figure 58-06.1. Calculate:

a) the capacitance of the capacitor when the supply current is a minimum;

b) the dynamic impedance, Z_d, of the network at resonance;

c) the supply current.

Problem 58-7    Source:   Example 17.8 - page 376 - HUGGES, A. E. - Book: Electrical and Eletronic Technology - 10ª ed. - Editora Pearson - 2008.

For the series RLC circuit shown in Figure 58-07.1 calculate:

a) the resonant frequency and bandwidth of the circuit;

b) the output voltage, V_o, at resonance and side frequencies;

c) the value of the side or half power frequencies.

Problem 58-8    Source:   Problem created by the site's authors.

For the circuit shown in Figure 58-08.1 calculate:

a) the value of Z so that the circuit is in resonance at a frequency of 100 Hz;

c) calculate the values ​​of L and C;

b) and the circuit bandwidth.