Download multiple choice questions for chapter 21

MULTIPLE CHOICE QUESTIONS FOR CHAPTER 21
All questions have only one correct answer
1.
[a]
[b]
[c]
[d]
2.
[a]
[b]
[c]
[d]
3.
A differential amplifier has an open-loop voltage gain of 100. The input signals are 2.5 V and
2.4 V. The output voltage of the amplifier is:
10 V
1 mV
10 V
1 kV
Which of the following statements relating to operational amplifiers is true?
It has a high open-loop voltage gain at low frequency, a low input impedence and low output
impedance
It has a high open-loop voltage gain at low frequency, a high input impedance and low
output impedance
It has a low open-loop voltage gain at low frequency, a high input impedance and low output
impedance
It has a high open-loop voltage gain at low frequency, a low input impedance and high
output impedance
[a]
[b]
[c]
[d]
A differential amplifier has a voltage gain of 120 x 10³ and a common-mode rejection ratio of
100 dB. The common-mode gain of the operational amplifier is:
1.2 x 10³
1.2
1.2 x 10¹⁰
1.2 x 10  5
4.
[a]
The output voltage, V o , in the amplifier shown in Figure 1 is:
- 0.2 V
[b]
+ 1.8 V
[c]
+ 0.2 V
[d]
- 1.8 V
Figure 1
5.
(a)
(b)
The 3 k resistor in Figure 2 is replaced by one of value 0.1 M. If the op amp has an input
bias current of 80 nA, the output offset voltage is:
79.2 V
8 V
(c)
(d)
8 mV
80.2 pV
Figure 2
6.
[a]
In the op amp shown in Figure 2, the voltage gain is:
-3
[b]
+4
[c]
+3
[d]
-4
Figure 2
7.
[a]
For the op amp shown in Figure 3, the output voltage, V o , is:
- 1.2 V
[b]
+5V
[c]
+2V
[d]
-5V
Figure 3
8.
[a]
[b]
[c]
[d]
A steady voltage of -1.0 V is applied to an op amp integrator having component values of
R=100 kΩ and C=10 µF. The value of the output voltage 10 ms after applying the input
voltage is:
10mV
1mV
10mV
1mV
9.
[a]
[b]
[c]
[d]
In the differential amplifier shown in Figure 4, the output voltage, V o , is:
+ 1.28 mV
1.92 mV
- 1.28 mV
+ 5 V
Figure 4
10.
[a]
[b]
[c]
[d]
Which of the following statements is false?
A digital computer requires a D/A convertor
When negative feedback is used in an op amp, a constant and predictable voltage gain
results
A digital voltmeter requires a D/A convertor
The value of frequency at which the open-loop gain has fallen to unity is called transition
frequency