22.
Assume that you are adjusting the frequency of transmission of a radio
transmitter by varying the capacitance of a tuned circuit.
If you need to lower
the frequency of transmission, you change the position of the rotor plates with
respect to the stator plates so as to
a.
mesh the plates more fully, thus
increasing
capacitance
and
reducing the capacitive reactance.
b.
mesh the plates more fully, thus
decreasing
capacitance
and
increasing the capacitive reactance.
c.
unmesh the plates, thus decreasing capacitance and increasing the
capacitive reactance.
d.
unmesh the plates, thus increasing capacitance and decreasing the
capacitive reactance.
23.
Which statement
accurately
describes
the
effect
of
resonance
in
a
series-tuned circuit?
a.
If the total resistance of the circuit is small, the line current
is also small.
b.
At resonance, the circuit acts like an inductor in series with a
resistor.
c.
At resonance, the circuit acts like a capacitor in series with a
resistor.
d.
The circulating current in the circuit is limited only by the
24.
The characteristics of a parallel-tuned circuit when tuned to resonance
are
a.
minimum circulating current and minimum impedance.
b.
maximum circulating current and maximum impedance.
c.
minimum circulating current and maximum impedance.
d.
maximum circulating current and minimum impedance.
308
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