Introduction to Electronics complete course is currently being offered by Georgia Institute of Technology through Coursera platform and is taught by: Dr. Bonnie H. Ferri and Dr. Robert Allen Robinson, Jr.
Introduction to Electronics All Weeks Quiz Answers

About this Course:
This course introduces students to the basic components of electronics: diodes, transistors, and op amps. It covers the basic operation and some common applications.
Introduction to Electronics Week 2 Quiz Answers
Q 1)



For the ideal operational amplifier circuit above, which of the following are true?



Q 2)



For the difference amplifier circuit above, if R1=R4=1000ohn and Rf=R9=2000ohm, what is the  gain, G, of the circuit where v0=G(v2-v1)?


Answer: 2


Q 3)




Consider the inverting differentiator shown above. 

If R=2000R=2000Ω and C=0.25C=0.25μF, and Vi(t) = e-2000t V what is the correct expression for Vo(t)Vo(t)?




Q 4) The input to the following op amp circuit is vi(t)=10cos(100t). If R=10kΩ and C = 2uF, determine the value of v0 in volts and select the most appropriate answer below.






Q 5)


For the inverting operational amplifier circuit above, if R2=10kΩ and the closed-loop gain is G=−5000, what is the value of R1?


Submit your answer in units of Ohms, while omitting the unit. For example, if your answer is 1000Ω submit 1000.


Answer: 2


Question 6)



For this question, Ra=3kΩ, Rb=12kΩ, Rc=3kΩ, and Rd=12kΩ. va=6V and vb=14V. What is vo? Give your answer in Volts and omit the units from your answer.


Answer: 32

Q 7) For the circuit shown, Vin=Vin(t) = sin(ωt)and R= 100 .A plot of the output voltage VO(t) is shown. 

What is the maximum current in milliamps that can be supplied by the voltage source?






Answer: 5   

Q 8)

An opamp is used as a buffer between the source and the load resistor

R in the circuit of question 7 as shown. The opamp must be able to supply at least what magnitude of current to ensure that VO(t) = Vin(t)?

Enter the answer in milliamps.



Answer: 10

Q 10)
For the circuit shown, V1 = 3V, V2 = -2V, R1 = 2kΩ, Rf = 10kΩ, and the output voltage VO = -7V. What is the value of the resistor R2 in kΩ?




Answer: 2.5    

Introduction to Electronics Week 3 Quiz Answers

Q 1)

Consider the following circuit where C=200nF.


For the circuit to have a bandwidth of ωb=500rad/s and a passband gain of -400, what must be the values of Rf and R1 ?


Enter the value of R1 in ohms.


Answer: 25


Question 2)

For the circuit of question 1, enter the value of Rf in KILO ohms.


Answer: 10


Question 3)

For the following circuit, R1=100Ω. Select the values of Rf and C to have a passband gain of -100 and a corner frequency of 1,000 rad/s.


Enter the value of C in uF.



Answer: 10   

Question 4)

For the circuit of question 3, enter the value of  Rf in .


Answer: 10


Question 5)

What Is the DC gain of a filter circuit that has the given transfer function?


Answer: 2


Question 6)

What is the bandwidth in radians-per-second of a filter circuit that has the given transfer function?

Answer: 5  


Question 7)

A sine wave with amplitude 2 V and frequency 1358 Hz is applied to the circuit

shown. If Rf=10 kΩ, R1=1.5 kΩ , and C = 0.1 μF , what is the amplitude of the output sine wave?


Answer: 10.5  

In the filter circuit shown, R1 = 10kΩ, R2 = 10kΩ, R3 = 4kΩ, R4 = 6.8kΩ, C1 = 5.3nF, and C2 = 5.3nF. 1 nF = 1 nanofarad = 10-9 farads. What is the dc gain of this filter? Calculate your answer to at least the nearest tenth.




Answer: 2.8


Question 9)

For the circuit of question 8, what is the resonance frequency in kilohertz? Calculate your answer to at least the nearest tenth.


Answer: 3


Question 10)

For the circuit of question 8, what is the quality factor? Calculate your answer to at least the nearest tenth.


Answer: 3.3


Question 11)

In the filter circuit shown, R1 = 10kΩ, R2 = 10kΩ, R3 = 2kΩ, R4 = 2kΩ, C1 = 0.15 μF,

and C2 = 0.1 μF. 1 μF = 1 microfarad = 10-6 farads. Which of the following are not true?




  • The resonance frequency increases as the value of C2 is decreased.
  • The DC gain is 2
  • There is a peak in the transfer function of this filter.
  • The resonance frequency is approximately 130 radians per second.

Introduction to Electronics Week 4 Quiz Answers

Question 1)

Consider a standard diode shown below. Select all of the statements that are true for diodes and diode circuits.



  • An ideal diode in forward bias can be thought of as a short circuit.
  • A diode cannot be used to block current flow in a specific direction.
  • Diodes are used in rectifier circuits, in voltage regulator circuits, in limiter circuits, and as light emitting diodes (LEDs).
  • The diode voltage, VD, of an ideal diode in forward bias is a positive value larger than 0.
  • Diodes have three operation regions: one is forward bias, one is reverse bias, and one is reverse breakdown.

Question 2)

For the following circuit with an ideal diode, determine at what time the diode starts conducting (goes into the "ON" state). Assume that the resistor is R = 1500Ω, the battery has a  constant voltage of B = 9V, and the varying source is Vs=tvolts, where t > 0. Enter the value of time (in seconds) without the units.




Answer:  3  


Question 3)

The following circuit has ideal diodes. The parameters are V1 = 3V, V2 = 5V, and R = 10Ω. 

If a diode is conducting, we say that it is "ON". If a diode is not conducting, we say that it is "OFF".  Select which answer is correct.


  • Both diodes are ON
  • Both diodes are OFF
  • Diode 1 is OFF and diode 2 is ON
  • Diode 1 is ON and diode 2 is OFF

Question 4)

For the circuit in question 3, solve for the current i, in amps.  Enter your answer in the box below without units.

Answer: 0.3

Question 5)

Consider the following circuit, where the diode is ideal:

The input to the circuit is shown below. Determine the time periods for which the output waveform equals the input, that is, when V0=Vin. Select all that apply.




  • t = [0.2, 0.25]
  • t = [0.05, 0.1]
  • t = [0, 0.05]
  • t = [0.15, 0.2]
  • t = [0.1, 0.15]


Question 6)

With the same circuit and input as in question 5 except using the ideal diode plus voltage source model with Vf = 0.5V, determine 

minimum voltage of V0.


Answer:   -0.5   

Question 7)

In the circuit shown, the diodes are ideal.


For V1=2V V1=2V, V2 = 5V V2=5V, R1 = 2k\OmegaR1=2kΩ, R2 = 1k\OmegaR2=1kΩ, what is I1I1 in amps?  



Answer:  0   

Question 8)

For the circuit and values of question 7, what is I2I2? Enter your answer in mA.


Answer:  5  

Question 9)

For the circuit of question 7,  V2 = 5VV2=5V, R1 = 2k\OmegaR1=2kΩ, R2 = 1k\OmegaR2=1kΩ, and I1=1mAI1=1mA. what is V1V1 in volts?


Answer:  7  

Question 10)

For the circuit shown, V3 = 6VV3=6V, I1 = 1mAI1=1mA, R3 = 2k\OmegaR3=2kΩ, R4 = 12k\OmegaR4=12kΩ, R5 = 4k\OmegaR5=4kΩ, and R6 = 6k\OmegaR6=6kΩ. Solve for the current I in milliamps, assuming that the diodes are ideal.



Answer: 0.56

Introduction to Electronics Week 5 Quiz Answers

Question 1)

Consider a diode circuit shown below. 


Assume that each diode can be modeled as an ideal diode in series with a voltage source, having Vf=0.7V.

The resistor has a value of R1=10Ω. 


Check all statements that are true



  • When any of the diodes are ON, the voltage across that diode is 0.7 V.
  • When Vin is in between the positive and negative limits of Vout, Vo=Vin.
  • If V1=2.3V and V2=2.3V, then Vo has a positive limit of 3 Volts and a negative limit of -3 Volts.
  • When R1 is replaced with a resistor with higher resistance, the Voltage Transfer Characteristics (VTC) curve changes.

Question 2)

Which of the following are TRUE? Select all that apply.


  • To have a smoother output voltage from an ac to dc converter, one must use a smaller filter capacitor.
  • The order of stages in a DC power supply from input to output is a transformer, rectifier, then lastly a filter.
  • If the input is a sinusoidal signal, the output of a half-wave rectifier will have the same frequency as the input.
  • If the input is a sinusoidal signal, the output of a full-wave rectifier will have the same frequency as the input.
  • If the diodes in the rectifiers are non-ideal, the output voltage of a full-wave rectifier is smaller than that of a half-wave rectifier.

Question 3)

A limiter is implemented using two non-ideal diodes, each modeled as an ideal diode in series with a voltage Vf volts. If the input voltage is a 5V amplitude sine wave, what is the minimum output voltage?


  • 2Vf
  • ​−5
  • Vf
  • ​-5 + 2Vf

Question 4)

In the rectifier below, the resistance Rs of the voltage source has been included to see how it affects the output voltage. If R=300Ω, RS= 100Ω, and Vin  is a sinusoidal voltage with amplitude 10V, what is the maximum output voltage Vout in volts?


The diodes are ideal.

(It may help to redraw the circuit with diodes replaced by short and open circuits as appropriate)


   

Answer: 7.5


Question 5)

For the circuit shown and the given input voltage, which of the following plots is the correct output voltage versus time? The diode in the circuit is modeled as an ideal diode in series with a voltage source Vf = 0.65V.







  • D
  • C
  • A
  • B

Question 6)

A diode circuit and sinusoidal input signal are shown. The diode is modeled as an ideal diode in series with a voltage source Vf = 0.7V.


What value resistor should be used so that the maximum diode current is 10 mA? Give your answer in ohms to the nearest ohm.




Answer: 230


Question 7)

For the circuit and input of problem 6:


If R = 510 Ω, what is the magnitude of the diode current at t = 400μs? Give your answer in milliamps.


Answer: 0


Question 8)

For the circuit and input of problem 6:


If R = 510 Ω, what is the magnitude of the diode current at t = 700μs? Give your answer in milliamps. 


Answer: 4.2


Question 9)

Select all of the statements that are NOT true.

  • Loading of a voltage source may be reduced by lowering the source resistance.
  • A diode circuit with three regions of operation (three states) has three corners on its VTC plot.
  • The envelope of an AM voltage waveform is a plot of the peak voltage of the carrier signal versus frequency.
  • A diode envelope detector with a relatively large time constant can act as a peak detector.
  • The voltage transfer characteristic of an ideal voltage regulator is a line of slope 1.

Question 10)

For the input and output waveforms shown, which of these sets of (Vin, Vout) points contains only points that are on the VTC?


  • 0.5,2) (3,3) (-2,0)
  • (1.5,5) (0.5,0.5) (3,2)
  • (0,0) (5,2) (-0.5,0)
  • (-2,-1) (0,0) (4,2)


Introduction to Electronics Week 6 Quiz Answers

Question 1)

In the n-channel MOSFET circuit, RD = 12kΩ, and the supply voltage VDD = 10V.

The transistor has the parameters K = 1.56mA/V2 and VTO = 1.4V.

What must the gate voltage VG be to set the drain voltage VD to 5V ?


Enter your answer in volts to two decimal places.



Answer: 1.92


Question 2)

A portion of a common source amplifier is shown in the figure. It is given that the source voltage VS = -4V,


VSS = −12V, RS =2kΩ, and R3 = 91Ω.

Determine the dc bias current through R3.(in mA)



Answer: 0


Question 3)

For the partial CS amplifier circuit of problem 2, 


Determine the dc bias current through RS. (in mA)


Answer: 4


Question 4)

For the partial CS amplifier circuit of problem 2, 


Determine the dc bias current of the transistor ID. (in mA)


Answer: 4


Question 5)

The binary inputs to the circuit below are A = 1, B = 0. Enter the corresponding value of C.



Answer: 1


Question 6)

The binary inputs to the circuit below are A = 0, B = 0, D = 0. Enter the corresponding value of E.



Answer: 1


Question 7)



For the CS amplifier shown, VDD = 15V, VSS = -15V, K = 1.1mA/V2, VTO = 2V, R = 15kohm,

R2 = 110kΩ, RD = 10kΩ, RS = 5kΩ, R3 = 200Ω, and RL = 10kΩ.


What is the dc gate voltage to two decimal places?


Answer: -2.31


Question 8)

For the CS amplifier of problem 7, what is the MOSFET drain current in mA to two decimal places?


Answer:  1.88


Question 9)

For the CS amplifier of problem 7, what is the dc drain voltage VD in volts to two decimal places?


Answer: -3.80


Question 10)

For the CS amplifier of problem 7, what is the magnitude of the ac midband gain to two decimal places?


Answer: 9.255


Introduction to Electronics Week 7 Quiz Answers

Q 1)



The dc bias circuit for a common emitter amplifier is shown in the figure. In the circuit,

VCC = 12V, RB2 = 105.8kΩ, VC = 6V, VE = 3V, VB = 3.65V, IE = 2mA, and B = 75.


Answer: 1.50


Q 2)

For the circuit of question 1,

Solve for the collector resistor RC. (In kilo ohms to two decimal places)


Answer: 3.04


Q 3)

For the circuit of question 1, 

Solve for the base bias resistor RB1. (In kilo ohms to two decimal places)


Answer: 69.36


Q 4)




In the CE amplifier shown,

VCC = 12V, RB1 = 15kΩ, RB2 = 51kΩ, RC = 8kΩ, RE1 = 1.7kΩ, RE2 = 150Ω, RL = 20kΩ, and B=75. Assume VBE = 0.65V.


Solve for the collector current in milliamps to two decimal places.


Answer: 1.11


Q 5)

For the CE amplifier of question 4, solve for the midband gain to one decimal place.


Answer: -35.06


Q 6)

In the BJT CE amplifier of question 4, as the emitter resistor RE2 is increased,

  • the midband gain increases and the dc collector current increases.
  • the midband gain increases and the dc collector current decreases.
  • the midband gain decreases and the dc collector current remains constant.
  • the midband gain decreases and the bias point of the transistor changes.


Q 7)

Select all of the below statements that are true.

  • A CE amplifier may behave as an attenuator for signals at some frequencies.
  • As the collector current of a particular biased BJT is decreased, its transconductance decreases.
  • The overdrive factor used when designing a BJT switch is to ensure that the BJT remains in cutoff no matter what load is placed on the switch. 
  • The saturation current parameter of a BJT may be determined from a point on its transfer characteristic curve.
  • A curve tracer may be used to measure the collector current of a BJT for different values of VCE as the base current is held constant.

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