Exam
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1)
The output of a peak detector is always
1)
A)
equal to the min value of the peak level received since the last reset pulse.
B)
70.7% of input.
C)
equal to the max value of the peak level received since the last reset pulse.
D)
None of the above.
Answer:
C
A)
B)
C)
D)
2)
Refer to (d) in the figure above. If Vin = 200 mV, RF= 52 k, and IEBO = 50 nA, the Vout would be
2)
A)
–5.41 mV.
B)
–7.75 V.
C)
–775 mV.
D)
7.75 mV.
Answer:
B
A)
B)
C)
D)
1
3)
Isolation amplifiers can accomplish isolation using
3)
A)
optical coupling.
B)
transformer coupling.
C)
capacitive coupling.
D)
All of the above.
Answer:
D
A)
B)
C)
D)
4)
Refer to (b) in the figure above. If RL= 20 k, R1= 1.2 k, and Vin = 2.5 V, the load current IL would
be
4)
A)
2.083 A.
B)
208.3 µA.
C)
2.083 mA.
D)
20.83 mA.
Answer:
C
A)
B)
C)
D)
5)
Refer to the figure above. Which of these circuits is known as a voltage–to–current converter?
5)
A)
(a)
B)
(b)
C)
(c)
D)
(d)
Answer:
B
A)
B)
C)
D)
6)
The current applied to a current–to–voltage converter circuit changes from 4 to 20 mA. If Rf is 625
, what is the change in output voltage?
6)
A)
1 V
B)
5 V
C)
20 V
D)
10 V
Answer:
D
A)
B)
C)
D)
2
7)
Log amplifiers are used to
7)
A)
linearize an exponential output from a transducer.
B)
compress an analog signal.
C)
perform analog multiplication and division.
D)
All of the above.
Answer:
D
A)
B)
C)
D)
8)
An input transducer converts
8)
A)
current to voltage.
B)
voltage to current.
C)
a nonelectrical quantity to an electrical quantity.
D)
an electrical quantity to a nonelectrical quantity.
Answer:
C
A)
B)
C)
D)
9)
The primary function of the oscillator in an isolation amplifier is to
9)
A)
rectify high frequency ac to dc.
B)
produce dual polarity dc voltages for the input to the demodulator.
C)
convert dc to low frequency ac.
D)
convert dc to high frequency ac.
Answer:
D
A)
B)
C)
D)
10)
An antilog amplifier is formed by connecting a pn junction (diode or BJT) to the
10)
A)
output.
B)
inverting and noninverting inputs.
C)
input.
D)
feedback loop.
Answer:
C
A)
B)
C)
D)
11)
An instrumentation amplifier has a high
11)
A)
power gain.
B)
output impedance.
C)
CMRR.
D)
supply voltage.
Answer:
C
A)
B)
C)
D)
3
12)
Instrumentation amplifiers are well suited for environments with
12)
A)
high signal levels that need to be attenuated.
B)
no power supply voltages.
C)
small signals superimposed on larger common–mode voltages.
D)
no signal and no noise.
Answer:
C
A)
B)
C)
D)
13)
Refer to the figure above. Which of these circuits is known as a peak detector?
13)
A)
(a)
B)
(b)
C)
(c)
D)
(d)
Answer:
C
A)
B)
C)
D)
4
14)
Refer to the figure above. Which of these circuits is known as a constant–current source?
14)
A)
(a)
B)
(b)
C)
(c)
D)
(d)
Answer:
B
A)
B)
C)
D)
15)
Refer to (a) in the figure above. If R1= R2 = 30 k and the closed loop gain is 450, the value of the
external gain–setting resistor RG is
15)
A)
133.63 k.
B)
13.36 .
C)
133.63 .
D)
None of the above.
Answer:
C
A)
B)
C)
D)
16)
Refer to (b) in the figure above. If Vin = 5 V and Rin = 22 k, the current thru the load RL would be
16)
A)
227.27 mA.
B)
227.27 µA.
C)
2.27 mA.
D)
22.72 mA.
Answer:
B
A)
B)
C)
D)
5
17)
Refer to the figure above. Which of these circuits is known as an isolation amplifier?
17)
A)
(a)
B)
(b)
C)
(c)
D)
(d)
Answer:
C
A)
B)
C)
D)
18)
The total voltage gain of an isolation amplifier is 49. If the voltage gain of the input and output
stages are equal, the voltage gain for each stage is
18)
A)
7.
B)
4.9.
C)
24.5.
D)
98.
Answer:
A
A)
B)
C)
D)
19)
The OTA has a ________ input impedance and a ________ CMRR.
19)
A)
low, high
B)
high, high
C)
high, low
Answer:
B
A)
B)
C)
20)
Refer to (a) in the figure above. If R1= R2= 28 k and RG= 100 , the Acl would be
20)
A)
56.1.
B)
561.
C)
5.60.
D)
560.
Answer:
B
A)
B)
C)
D)
6
21)
A voltage–to–current converter is used in applications where it is necessary to have an output load
current that is controlled by
21)
A)
output resistance.
B)
input frequency.
C)
input voltage.
D)
input resistance.
Answer:
C
A)
B)
C)
D)
22)
Refer to the figure above. Which of these circuits is known as an instrumentation amplifier?
22)
A)
(a)
B)
(b)
C)
(c)
D)
(d)
Answer:
A
A)
B)
C)
D)
7