Electronics Final Exam Test 2
If R1 shorts in figure 8-2, VR2...
increases
If the frequency increases in figure 12-1, the phase angle...
increases
If the resistor shorts in figure 13-2, the current...
increases
The circuit in figure 12-3 is known as a .... filter
low-pass
The circuit in figure 10-3 is known as a...
low-pass filter
What is the capacitance of a capacitor that drops 50V and stores .500 uC of charge?
.01 uF
What is one time constant of a 4.7 uF capacitor in series with a 22kO resistor?
103 ms
If a 1 uF capacitor and a 10 kO resistor are connected in series across 20 VDC, approximately how much voltage will the capacitor drop after charging for just one time constant?
12.6 V
How long will it take for a 22 uF capacitor to completely charge through a 47 kO resistor?
5.17 s
What is the source voltage in a series resonant circuit if Vc=150 V, VL=150 V, and VR= 5
50 V
What is the cutoff frequency in figure 10-3?
85 Hz
A sine wave's peak value is smaller than its RMS value.
False
An ohmmeter can be used to accurately test the impedance of an RL circuit.
False
Capacitance is the ability to store voltage.
False
Current flows both ways simultaneously in an AC circuit.
False
Electrolytic capacitors are ideal for alternating current applications.
False
If a dc voltage is input to a transformer's primary, then an ac voltage is induced in its secondary.
False
Which statement describes the relationship of IL and IR in figure 12-2?
IL lags IR
With three capacitors in series, the current lags the voltage by:
None of the above
A capacitor blocks dc and passes ac.
True
A high pass filter will cause some phase shifting of the signal.
True
A series RLC circuit can be configured for band-pass or band-stop filtering purposes.
True
As the frequency applied to an RC circuit increases, the impedance decreases.
True
At resonance, Xc equals XL
True
The voltage leads the current in an inductive circuit
True
If an RC integrator uses a 47 uF capacitor, a 12 kO resistor and a square wave input with a frequency of 200 kHz, its approximate output is...
a near dc voltage of about half the peak square wave voltage
If an inductor has an ac current flowing through it, the magnetic field is...
constantly changing
If the output were taken across the resistor in figure 10-3, the circuit would be known as a...
high-pass filter
Which one of the following represents the value at point G in figure 8-1?
the RMS voltage
When connecting a large electrolytic capacitor to a circuit with a 100 Vdc source, place the negative end of the capacitor...
towards the negative side of the source.
If a tuned tank circuit has a very narrow bandwidth, its Q is probably...
very high
What is the primary current in figure 14-1 if Is=40 mA and the turns ratio equals 4:1?
10mA
How much voltage does the resistor drop in figure 10-2?
20 V
What is the output voltage at the cutoff frequency in figure 10-3.
6.45 V
Calculate Vr2 in figure 8-2.
6.84 Vp
What is the total inductance if a 50 mH inductor is connected in series with a 15 mH inductor?
65 mH
If a 22uF capacitor is connected to a 15 V 400 Hz source, its current equals...
829 mA
If the operating frequency increases in Figure 10-1, how does the phase angle change?
It decreases.
If the operating frequency increases in Figure 10-1, how does the current change?
It increases.
If the resistance decreases in figure 13-2, the bandwidth...
decreases
When the input pulse width to an RC integrator is much less than 5pie, the output approaches the shape of the input.
False
What is the inductive reactance of a 150 mH inductor operating at 10kHz?
9420 ohm
A center tap transformer has a connection at the midpoint of the secondary winding resulting in:
All of these
Vpp is measured between points ... in figure 8-1.
D and F
The total inductance of two parallel inductors equals the sum of their inductive values.
False
A sine wave's frequency equals the reciprocal of its period.
True
A step-down transformer could have a primary-secondary turns ratio of 4:1.
True
