Exam 26: Resonance

The advantage of a parallel resonant LC circuit is that Z is minimum only for an ac signal at the resonant frequency.

Because of the energy stored by L and C, the circulating tank current can provide full sine waves of current and voltage output when the input is only a pulse.

What causes the coil resistance to become higher than the coil's dc resistance at higher frequencies?

Resonant frequency is equal to one divided by the product of two pi times the square root of L times C.

X_L and X_C can be combined to favor one particular frequency, the resonant frequency to which the LC circuit is tuned.

The frequency at which the opposite reactances are equal is the

What is a semiconductor device that varies in capacitance when its voltage is changed?

What does 4?² equal?

What is the result of plotting frequencies at and near the resonant frequency on a graph?

When a parallel circuit is mistuned

High Q results in

A test instrument used to measure inductance or capacitance is the Q meter.

______________ means obtaining resonance at different frequencies by varying either L or C.

The Q of a resonant circuit can be considered a ______________ factor that determines how much the voltage across L or C is increased by the resonant rise of current in a series circuit.

The bandwidth between two frequencies having 70.7% response in current or voltage is also the bandwidth in terms of ______________-power points.

The width of the resonant band of frequencies centered around f_r is called the

The group of frequencies with a response of what percentage of maximum, or more, is generally considered the bandwidth of a tuned circuit?

At series resonance, the resonant current is

The frequency at which the opposite reactances are equal is the harmonic frequency.

What is the Q of a series circuit that is resonant at 1.0 MHz and develops 50 mV across a 250-?H L with a 2-mV input?