Electronics 2: Electronic Circuit Analysis and Design Final Exam
Name: ______________________________________ C/Y/S: ____________ Date Submitted: ____________________________
Part 1 - Multiple Choice Instructions: Select the best answer by marking the letter that corresponds to your choice on the provided
answer sheet. If your answer is not in the choices mark e. (25 pts)
1. A differential amplifier _________________. 7. It is the current needed to force the output of a BJT input op-amp
a. is a part of an Op-amp to zero.
b. has one input and one output a. Input leakage current
c. has two outputs b. Input offset current
d. both a and b are correct c. Input bias current
d. Input holding current
2. Op-Amp is a ______ type of amplifier.
a. Current 8. An op-amp configured as inverting has the following parameters: a
b. Voltage feedback resistor of 10 KΩ, input resistance of 1 KΩ, an open loop
c. Power output impedance of 75 Ω and an open loop gain of 100,000.
d. Resistance Calculate the feedback fraction.
a. 0.00128
3. Op-Amp is ______ coupled voltage type of amplifier. b. 0.00239
a. AC c. 0.09
b. DC d. 0.0082
c. ADC
d. DAC 9. Calculate the closed loop gain of an inverting op-amp with input
resistor of 1 KΩ, feedback resistor of 10 KΩ and an open loop gain of
4. Op-Amp has _______ gain. 10,000.
a. High a. 10
b. Low b. 9.989
c. Zero c. 9.329
d. Medium d. 10.909
5. What is the ideal input impedance at the non-inverting input of a 10. The non-inverting and inverting inputs of an op-amp have an
transresistance op-amp? input voltage of 1.5 mV and 1.0 mV, respectively. If the op-amp has a
a. 1 common-mode voltage gain of 10 and a differential-mode gain of
b. extremely high 10,000, what is its output voltage?
c. 0 a. 5.0 V
d. infinite b. 5.0125 mV
c. 5.0125 V
6. What is the ideal input impedance at the inverting input of a d. 25.0125 V
transresistance op-amp?
a. 1 11. What is the op-amp’s common-mode voltage gain given a
b. extremely high differential-mode voltage amplification of 2000,000? The op amp is
c. 0 μA741 with 90 dB CMRR.
d. infinite a. 31, 622.778
b. 63.246
c. 6.324
d. 0.158
Darwin D. Mañaga, Meng-ECE, PECE, ACPE
12. In op-amps, the term “virtual ground” is applicable to 18. It is the output current flowing when the output of an op-amp is
____________. shorted to ground
a. inverting config. a. Short Circuit Current
b. non-inverting config. b. Input Bias Current
c. both a and b c. Input Offset Current
d. none of the above d. Transient Current
13. Calculate the sacrifice factor of a negative-feedback amplifier 19. It is a signal applied differentially to the inputs, for the purpose of
having an open loop gain of -2000 and a measuring that signal.
feedback factor of -1/10. a. Common Mode Signal
a. -199 b. Normal Mode Signal
b. 201 c. CMRR
c. 200 d. NMRR
d. -200
20. When the common mode gain is increased, CMRR will be
14. An FET phase-shift oscillator having gm = 6000 S, rd = 36 kΩ, ________
and feedback resistor R = 12 kΩ is to operate at 2.5 kHz. Calculate C a. Increased
for specified oscillator operation. b. Decreased
a. 0.0076 μF c. Kept Constant
b. 0.0066 μF d. None of the above
c. 0.0026 μF
d. 0.0013 μF 21. When the differential gain is increased, CMRR will be ________
a. Increased
15. Calculate the frequency of a Wien bridge oscillator circuit when R b. Decreased
= 10 kΩ and C = 2400 pF. c. Kept Constant
a. 6.6 kHz d. None of the above
b. 2.7 kHz
c. 41.67 kHz 22. Op-Amp is originated from ________ computers.
d. 17.7 kHz a. Analog
b. Digital
16. Calculate the oscillator frequency for a Hartley oscillator as for c. Both a and b
the following circuit values: C = 250 pF, L1 = 1.5 mH, L2 = 1.5 mH, d. None of the above
and a mutual inductance of 0.5 mH.
a. 183 kHz 23. Op-Amp performs ________ operations.
b. 228 kHz a. Arithmetic
c. 159 kHz b. Logical
d. 170 kHz c. Alphanumeric
d. Both a and b
17. The term “monolithic” is derived from a combination of the Greek
words “monos” and “lithos” which means ___________. 24. An Op-amp configuration that is used to transform a
a. single-stone load capacitance into an inductance.
b. single-wafer a. Schmitt trigger
c. single-element b. Gyrator
d. single-chip c. Window
d. Magnetic amplifier
25. It is an electronic circuit used to implement a variety of simple
two-state systems such as oscillators,
timers and flip-flops.
a. Eccles-Jordan
b. Multi-vibrator
c. Magnetic amplifier
d. PLL
Darwin D. Mañaga, Meng-ECE, PECE, ACPE
Darwin D. Mañaga, Meng-ECE, PECE, ACPE
Part 2 - Problem Solving Instructions: Answer below problems neatly and completely. Write all the necessary solutions and box your
final answer.
1. Design an op amp circuit with inputs V1 and V2 such that the output voltage, Vo = – 2V1 + 1.5V2. (25 pts)
Darwin D. Mañaga, Meng-ECE, PECE, ACPE
2. For the circuit in Figure 1, calculate the output voltage, Vout (t). (25 pts)
Figure 1. Op Amp Circuit for Item#2
Darwin D. Mañaga, Meng-ECE, PECE, ACPE
3. The circuit below is known as the Kelvin 4-wire connections. The simplest way to define Kelvin connections is to create
contact between electrical potential and a current-carrying component. This contact reduces or removes the effects of contact
resistance, RP. If you're dealing with low millivolt measurements like those found in a shunt resistor, the contact resistance is
an unknown yet significant variable. The best way to handle this is by using a four-terminal device. Two terminals conduct
high currents in this device, while the other two run the voltage measurements. Calculate the load voltage, VRL, Vo1, and
Vo2 for the Kelvin circuit connections in Figure 2. Note: AWG stands for American Wire Gauge - also known as the Brown
& Sharpe wire gauge, is a logarithmic stepped standardized wire gauge system used since 1857, predominantly in North
America, for the diameters of round, solid, nonferrous, electrically conducting wire). (25 pts)
Figure 2. Kelvin Connections Circuit Using Op-Amp
Darwin D. Mañaga, Meng-ECE, PECE, ACPE
