Basics of
Electronics Engineering (12EC14) 30.10.2012

Tutorial-5

1.
Determine
the output v_{o}_{ }in terms of v_{1},
v_{2}, v_{3} and v_{4}, in the circuit of fig1. Assume
the op amp to be ideal. Calculate v_{o}, if v_{1}
= 1V, v_{2 }= 2V, v_{3} = 3V, and v_{4} = 4V, assuming
all the resistors are equal.

2. In the voltage amplifier circuit of fig2,
using an ideal op amp, determine the gain as a function of the
potentiometer-setting, x. What is the range of the gain obtained? Show how to
add a resistance, so that the gain range can be 1 to 21. What should be the
resistor value?

3. In the voltage follower circuit of fig3, op
amp used is ideal in all respects, except it has a finite gain, A. Determine v_{o}/v_{in}. If A
is equal to 1000, calculate the error of the gain from that of the voltage
follower with an ideal op amp.

4. Determine v_{o}/v_{in} in
the circuit of fig4. Assume op amp is ideal.

5. Determine v_{o}/v_{in }in
the circuit of fig5. The op amp used is ideal in all respects, except that it
has a finite gain, A.

6. Determine v_{o}/v_{in }in
the circuit of fig6. The op amp used is ideal in all respects, except that it
has a finite gain, A.

7. Draw the summer circuits, using two ideal
op amps, and calculate the different resistor values to obtain a) v_{o}
= 2v_{1}-4v_{2}+6v_{3
}b) v_{o} = v_{1}+3v_{2}+5v_{3}-7v_{4}-9v_{5}-11v_{6},
where v_{1},v_{2},v_{3},v_{4},v_{5}_{
}and v_{6} are the available inputs.

8. In the circuit of fig7, show that the
differential gain is equal to R_{2}/R_{1}, if R_{1}/R_{2}
= R_{3}/R_{4}. Assume the op amp used is ideal.

9. Calculate the values of the different
resistors in the circuit of fig7, so that A_{d} =100 with A_{cm}
= 0 and the input resistance is equal to 25KΩ.

10. In the circuit of fig8, determine I_{L}
in terms of v_{in}_{, }if R_{1}
= R_{2}.

11. The output signal of an op amp with a slew
rate of 2.5V/µs, has a peak to peak value of 18V. Find
the maximum frequency for undistorted output voltage.

12. An op amp has a differential gain of 2×10^{4}
and a CMRR of 86dB. Determine the output, if the differential input is 10µV and
the common mode input is 10mV.

13. In the circuits of figs 9, 10 and11,
determine the output voltage, v_{o}. Assume the op amps to be ideal.

14. Draw the circuit of an Instrumentation
amplifier, using three ideal amplifiers, and calculate the values of the
different resistors to obtain a differential gain of 46dB with an infinite
CMRR.

15. Design a Schmitt trigger circuit using an
ideal op amp to obtain a hysteresis of 5V. The op amp is operating with +15V
and -12V. For the designed circuit, determine the UTP and LTP.

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