11. What happens when the frequency increases?
A. AOL(f) continues to drop
B. A increases
C. fo –> 0Hz
D. None of the mentioned
12. What will be the absolute value of phase shift, if the frequency keeps increasing?
A. Increase towards 45o
B. Decrease towards 45o
C. Increase towards 90o
D. Decrease towards 90o
13. Which of these statements is false?
A. The open-loop gain AOL(f) dB is approximately constant from 0Hz to fo
B. When input signal frequency and f is equal to break frequency fo, the gain frequency is called -3dB frequency
C. The open-loop gain AOL(f) dB is approximately constant upto break frequency fo, but thereafter it increases 20dB each time there is a tenfold increase in frequency.
D. At unity gain crossover frequency, the open-loop gain AOL(f) dB is zero
14. What is the maximum phase shift that can occur in an op-amp with a single capacitor?
A. 180o
B. 60o
C. 270o
D. 90o
15. How can the gain roll-off be represented in dB/octave?
A. 12 dB/octave
B. 6 dB/octave
C. 10 dB/octave
D. 8 dB/octave
16. Select the correct magnitude and phase for the frequency range.
List-I | List-II |
1. f1 | i. Gain is 3dB down from the value of AOL in dB |
2. f=f1 | ii. Gain roll-off at the rate of 20 dB/decade |
3. f>>f1 | iii. Magnitude of the gain is 20logxAOL in dB |
A. 1-iii, 2-i, 3-ii
B. 1-I, 2-ii, 3-iii
C. 1-iii, 2-ii, 3-i
D. 1-ii, 2-iii, 3-i
17. The specific frequency at which AOL (dB. is called
A. Gain bandwidth product
B. Closed-loop bandwidth
C. Small signal bandwidth
D. All of the mentioned
18. Find out the expression for open loop gain magnitude with three break frequency?
A. A/[1+ j(f/fo1)]x[1+ j(f/fo2)]x[1+ j(f/fo3)].
B. A/[1+ j(f/fo)]3
C. A/A/[1+ j(f/fo1)]+ [1+ j(f/fo2)]+ [1+ j(f/fo3)].
D. All of the mentioned
19. Find out the frequencies that are avoided in the frequency response plot?
A. None of the mentioned
B. Single break frequency
C. Upper break frequency
D. Lower break frequency
20. In a phase response curve of MC1556, the phase shift is -162.5o about 4MHz. If the approximate value of the first break frequency is 5.5Hz. Determine the approximate value of the second break frequency?
A. 945.89MHz
B. 945.89kHz
C. 945.89GHz
D. 945.89Hz
21. Consider a practical op-amp having two break frequencies due to a number of RC pole pairs. Determine the gain equation using the given specifications:
A ≅ 102.92dB; fo1 =6Hz ; fo2 =2.34MHz .
A. 140000/[1+ j(f/6)]x[1+ j(f/2.34)].
B. 140000/[1+ j(f/6)]x[1+ j(f/234)].
C. 140000/[1+ j(f/6)]x[1+ j(f/23400)].
D. 140000/[1+ j(f/6)]x[1+ j(f/2340000)].
22. What is the voltage transfer function of the op-amp in the s-domain.
A. S×A/(s+ωo)
B. A/(s+ωo)
C. (A×ωo)/(s+ωo)
D. None of the mentioned
23. Calculate the unity-gain bandwidth of an op-amp. Given, A≅ 0.2×106 & fo =5Hz?
A. 106
B. 108
C. 10-5
D. 10-10