1. PARISUTHAM INSTITUTE OF TECHNOLOGY AND SCIENCE DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING II YEAR/ III SEMESTER LINEAR INTEGRATED CIRCUITS AND APPLICATIONS TECHNICAL QUIZ—I(UNIT 1 & 2)

2. 1.A transconductance amplifier is one which has (a) Input is a current I and output is voltage V (b) Input is voltage V and output is current I (c) Input is voltage V I and output is voltage V 0 (d) Input is current I in and output is current I 0 2.A transresistance amplifier is one which has (a) Input is a current I and output is voltage V (b) Input is voltage V and output is current I (c) Input is voltage V I and output is voltage V 0 (d) Input is current I in and output is current I 0

3. 3.IC-741 op-amp has typical gain of in dB (a) 110 dB (b) 100 dB (c) 106 dB (d) 90 Db 4.Ideal terminal conditions of IC-op-amp are (a) V d = ∞, V 0 = 0, i P = i N = currents drawn by inverting and non-inverting inputs. i P = i N = 0. (b) V d = 0, V 0 = ∞, i p = i N = ∞ (c) V d = 0, V 0 = 0, i P = i N (d) none of the above

4. 5.The other name of voltage follower is (a) differential amplifier (b) inverting amplifier (c) non-inverting amplifier (d) unity gain amplifier 6.If the input is a sine wave, the circuit (output) will produce __________ phase shift (a) 360° (b) 0° (c) 90° (d) 180°

5. 7.An op-amp current to voltage converter is also called (a) transconductance amplifier (b) transimpedance amplifier (c) transresistance amplifier (d) none of the above 8.A VI op-amp converter is also called (a) transconductance amplifier (b) transresistance amplifier (c) transimpedance amplifier (d) none of the above

6. 9.The differential mode and common mode voltage is defined as (a) V DM = V 2 − V 1, V CM = V 1 + V 2 /2 (b) V DM = V 1 + V 2 /2, V CM = V 2 − V 1 (c) V DM = V 1 / 2 = V 2 / 2, V CM = V 2 − V 1 / 2 (d) none of the above 10.For a true difference amplifier, the following holds true: (a) A cm → 0, C M RR dB → 0 (b) A cm → ∞, C M RR dB → ∞ (c) A cm → ∞, C M RR dB → 0 (d) A cm → ∞ 0, C M RR dB → ∞

7. 11.An ideal op-amp should have (a) Zero input impedance and output impedance (b) Infinite input and output impedance (c) Infinite input impedance and zero output impedance (d) Zero input impedance and infinite output impedance 12.An ideal op-amp should have (a) low gain at low frequencies (v) low gain at low frequency and high gain at high frequencies (c) high gain at low frequency and low gain at high frequencies (d) high gain at all frequencies

8. 13.The actual gain of an op-amp at dc is of the order (a) 10 to 100 (b) 100 to 1000 (c) 100 to 100,000 (d) 1000,000 to 100,000,000 14.The ideal input impedance range of op-amp is (a) 1 kΩ (a) 10 kΩ to 10 6 mΩ (b) 10 6 mΩ to 10 12 mΩ

9. 15.Drift of amplifier means (a) variation of gain with load (b) variation of gain with frequency (c) change in sensitivity due to variation in temperature (d) none of the above 16.Which of the following amplifier compensates for drift? (a) Low gain amplifier (b) High gain amplifier (c) DC amplifier (d) Differential amplifier

10. 17.In addition to reduction to drift, the advantage of a differential amplifier is (a) mixing of two input voltages (b) an output of either polarity (c) rejection of common mode signal (d) all of the above 18.An ideal amplifier should have (a) infinite gain at all frequencies (b) large bandwidth (c) zero phase shift (d) all of the above

11. 19.An amplifier is an unstable condition when (a) gain is low (b) load is variable (c) phase shift is 180° (d) supply is rectified DC 20.Noise in op-amp due to (a) pick up from main supply (b) sparking in the circuit (c) internal generation (d) all of the above

12. 21.Noise in op-amp can be reduced to (a) shielding (b) uselpf (c) proper grounding (d) all of the above 22.An op-amp is generally not used as (a) summer (b) differentiator (c) subtractor (d) integrator

13. 23.Which of the following system is linear? (a) log amplifier (b) I to V converter (c) V to I converter (d) All of the above 24.A logarithmic amplifier can be used as (a) divider (b) multiplier (c) subtractor (d) none of the above

14. 27.An integrator is mostly preferred over differentiator because (a) more stable (b) less voltage drift (c) less noise (d) all of the above 28.A chip having more than 150 logic gates is known as (a) LSI chip (b) MSI chip (c) SSI chip (d) none of the above

15. 29.If a square wave is integrated by integrator using operational amplifier, the output is (a) triangular wave (b) ramp (c) sine wave (d) none of the above 30.Monolithic IC waters are typically of (a) 1/8 inch diameter (b) 1/4 inch diameter (c) 1 inch diameter (d) 2 inch diameter

16. 31.A good op-amp has (a) very high bandwidth (b) narrow bandwidth (c) high selectivity (d) all of the above 32.When an op-amp is operated in common mode fashion, CMRR should be (a) zero (b) infinitely high (c) very small (d) 5 dB

17. 33.Which amplifier will be preferred for highest gain? (a) darlington's pair (b) operational amplifier (c) cascade amplifier (d) none of the above 34.Decibel is defined in terms of (a) voltage ratio (b) current ratio (c) power ratio (d) none of the above

18. 35.A multivibrator produces (a) pure sine waves (b) square waves (c) distortion sine waves (d) saw tooth voltages 36.A linear system can be described by (a) state transition cavation (b) differential equation (c) dynamic equation (d) none of the above

19. 37.At which of the following frequency, the gain of op-amp will be zero? (a) β cut-off frequency (b) α cut-off frequency (c) unity gain cross over frequency (d) gain cross over frequency 38.The loss of precision in a quantity is called (a) down time (b) delay (c) unavoidable delay (d) none of the above

20. 39.A system is critically damped. Now if the gain of the system is increased, the system will behave as (a) over damped (b) under damped (c) oscillatory (d) critically defined 40.Silicon is preferred for semiconductor devices (a) abundant availability (b) easy formation of oxide layer (c) hood mechanical strength (d) all of the above

21. 41.A monolithic circuit means (a) circuit from single crystal (b) circuit from more than one crystal (c) uses double price of crystal to form a circuit (d) none of the above 42.Photolithography involves (a) making photographic mask and photoetching (b) onlyphotoetching (c) only masking (d) none of the above

22. 43.Aluminium is generally used of metallization (a) good mechanical bonds with silicon (b) relatively good conductor (c) depositaluminium films on the surface (d) all of the above 44.The standard package configurations of manufacturing IC. (a) glass metal package (b) ceramic flat package (c) dual in line (d) all of the above

23. 45.Sheet Resistance of IC is defined in (a) Ohms per square mm. (b) Ohms Square mm. (c) Ohms per mm. (d) Ohms per cubic mm. 46.The sheet resistance of emitter diffusion is of the order 200 Ω/sq, the emitter resistance is 4 kΩ. Then sheet resistance is (a) 20 ohm/sq. (b) 40 ohm/sq. (c) 30 ohm/sq. (d) 15 ohm/sq.

24. 47.The preference of polysilicon over aluminium (a) lowers threshold voltage (b) reduces capacitances (c) good bond and mechanical strength, a form of silicon (d) all of the above 48.The CMRR of MA 741 is (a) 70 db (b) 50 db (c) 40 db (d) none of the above

25. 49.The common mode gain and differential mode gain of op-amp. is (a) A DM = A 1 − A 2 /2, A CM = A 1 + A 2 (b) A DM = A 1 − A 2, A CM = A 1 + A 2 /2 (c) A DM = A 1 + A 2 /2, A CM = A 1 − A 2 (d) A DM = A 1 /2 − A 2 /2 A CM = A 1 − A 2 /2 50.The basic elements of op-amp is (a) differential amplifier (b) buffer, level translator (c) output driver (d) all of the above

26. 51.For large CMRR, A CM should be (a) as large as possible (b) as small as possible (c) zero (d) level to A dm 52.MOSFET op-amp is preferred over BJT, FET because (a) high input resistance 10 12 Ω (b) low input current, 1PA (c) high slew rate, 10 V/μS (d) all the above

27. 53.A current mirror can be used as an active load because it has (a) low resistance (b) high ac resistance (c) low ac resistance (d) high dc resistance 54.DC character of op-amp are (a) input bias and offset current (b) input offset voltage (c) thermal drift (d) all of the above

28. 55.Thermal drift of op-amp parameters (a) forced air cooling only (b) careful printed circuit board layout (c) both a and b (d) keep op-amp away from source of heat 56.AC characteristics of op-amp includes (a) Frequency response (b) slew rate (c) both a and b (d) none of the above

29. 57.An ideal op-amp should have open loop gain (a) around 90 dB constent over audio and R f frequency (b) less than 90 dB, varies on audio and R f frequency (c) 20 dB, constent audio and R f frequency (d) none of the above 58.The frequency response of op-amp includes (a) magnitude character only (b) phase character only (c) both (a) and (b) (d) none of the above

30. 59.The slew rate for IC 741 is (a) 0.5 V/μs (b) 0.9 V/μs (c) 0.8 V/μs (d) 1 V/μs 60Op-amp 741C cannot be used for high frequency applications because (a) low slew rate (b) high slew rate (c) O.T. V/QS (d) none of the above

31. 61.Number of diodes required in half-wave rectifier circuit using op-amp is (a) 1 (b) 2 (c) 3 (d) 4 62.Number of diodes required in full-wave rectifier using op-amp is (a) 2 (b) 3 (c) 1 (d) 4