1. In a negative feedback amplifier using voltage-series (Voltage sampling and series mixing) feedback,

a. R

b. R

c. R

d. R

Solution: https://www.youtube.com/watch?v=_22d9h7qEFU

2. A 741 OP-AMP has a gain-bandwidth product of 1 MHz. A non-inverting amplifier using this OP-AMP and having a voltage gain of 20 dB will exhibit a –3 dB bandwidth of

a. 50 kHz

b. 100 kHz

c. 100/17 kHz

d. 1000/7.07 kHz

Solution: https://www.youtube.com/watch?v=jg0FBlbWzMU

3. Three identical RC coupled transistor amplifiers are cascaded. If each of the amplifiers has a frequency response as shown in the figure, the overall frequency response is as given in

Solution: https://www.youtube.com/watch?v=EtdsNaauT8g

4. The circuit in the figure employs positive feedback and is intended to generate sinusoidal oscillations. If at a frequency f

a. R

b. R

c. R

d. R

Solution: https://www.youtube.com/watch?v=E28FKsiD0cQ

5. An amplifier using an OP-AMP with a slew rate SR = 1 V/µsec has a gain of 40 dB. If this amplifier has to faithfully amplify sinusoidal signals form dc to 20 kHz without any slew rate induced distortion, then the input signal level must not exceed

a. 795 mV

b. 395 mV

c. 79.5 mV

d. 39.5 mV

Solution: https://www.youtube.com/watch?v=vG62ly43ziE

6. The voltage gain A

a. + 16

b. – 16

c. + 8

d. – 6

Solution: https://www.youtube.com/watch?v=9K_U1BcpZSI

7. A triangular voltage waveform V

a. Determine the output V

b. Neatly sketch the output waveform superimposed on the input V

8. Below figure shown is a 2 – stage amplifier.

The transistors Q

a. Identify the configuration in each of the amplifier stages. (i.e. whether CE, CC or CB)

b. Determine the quiescent quantities of I

c. Determine an expression for the voltage gain V

Answer:

9. Consider the circuit shown. Assume the operational amplifier is ideal.

a. In which mode is the BJT operating (active or saturation or cutoff)? Justify your answer.

b. Obtain an expression relating the output current I

c. Determine Io and V

a. R

_{i}decreases and R_{o}decreasesb. R

_{i}decreases and R_{o}increasesc. R

_{i}increases and R_{o}decreasesd. R

_{i}increases and R_{o}increases2. A 741 OP-AMP has a gain-bandwidth product of 1 MHz. A non-inverting amplifier using this OP-AMP and having a voltage gain of 20 dB will exhibit a –3 dB bandwidth of

a. 50 kHz

b. 100 kHz

c. 100/17 kHz

d. 1000/7.07 kHz

3. Three identical RC coupled transistor amplifiers are cascaded. If each of the amplifiers has a frequency response as shown in the figure, the overall frequency response is as given in

4. The circuit in the figure employs positive feedback and is intended to generate sinusoidal oscillations. If at a frequency f

_{o}, β(f) = V_{f}(f)/V_{o}(f) = 1/6 ∟0^{o}, then to sustain oscillations at this frequencya. R

_{2}= 6R_{1}b. R

_{2}= 5R_{1}c. R

_{2}= R_{1}/6d. R

_{2}= R_{1}/55. An amplifier using an OP-AMP with a slew rate SR = 1 V/µsec has a gain of 40 dB. If this amplifier has to faithfully amplify sinusoidal signals form dc to 20 kHz without any slew rate induced distortion, then the input signal level must not exceed

a. 795 mV

b. 395 mV

c. 79.5 mV

d. 39.5 mV

6. The voltage gain A

_{v}= V_{o}/V_{i}of the JFET amplifier shown in the figure is I_{DSS}= 10 mA, V_{P}= 5 volts. Assume C_{1}, C_{2}and C_{s}to be very large.a. + 16

b. – 16

c. + 8

d. – 6

7. A triangular voltage waveform V

_{i}(t) is applied at the input to the circuit shown. Assume the diodes to be ideal.a. Determine the output V

_{o}(t)b. Neatly sketch the output waveform superimposed on the input V

_{i}(t) and label the key points.**Solution:****https://www.youtube.com/watch?v=DwkF8O6Xlvw**8. Below figure shown is a 2 – stage amplifier.

The transistors Q

_{1}and Q_{2}are identical with current gain β = 100, further β_{DC}= β_{ac}= β. The zener diode D_{z}has a break down region and its dynamic resistance r_{z}is zero. The capacitors C_{1}and C_{2}are large and provide negligible impedance at signal frequencies.a. Identify the configuration in each of the amplifier stages. (i.e. whether CE, CC or CB)

b. Determine the quiescent quantities of I

_{C1}and V_{C1}.c. Determine an expression for the voltage gain V

_{o}/V_{s}and determine its value. (Assume V_{BE}= 0.7 volts, r_{o}= ∞ and thermal voltage V_{T}= 25mV)Answer:

**Solution:**9. Consider the circuit shown. Assume the operational amplifier is ideal.

a. In which mode is the BJT operating (active or saturation or cutoff)? Justify your answer.

b. Obtain an expression relating the output current I

_{o}and the input voltage V_{i}.c. Determine Io and V

_{op}if V_{i}= 2 volt. Assume β = 99 and V_{BE}= 0.7 volts.**Solution:****https://www.youtube.com/watch?v=F4ZuatGRJO0**