parisutham institute of technology and science department of electrical and electronics engineering...

PARISUTHAM INSTITUTE OF TECHNOLOGY AND SCIENCE DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING

II YEAR/ III SEMESTERLINEAR INTEGRATED CIRCUITS AND APPLICATIONS

TECHNICAL QUIZ—I(UNIT 1 & 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 VI and output is voltage V0

(d) Input is current Iin and output is current I0

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 VI and output is voltage V0

(d) Input is current Iin and output is current I0

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) Vd = ∞, V0 = 0, iP = iN = currents drawn by inverting and non-

inverting inputs. iP = iN = 0.

(b) Vd = 0, V0 = ∞, ip = iN = ∞

(c) Vd = 0, V0 = 0, iP = iN

(d) none of the above

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°

7.An op-amp current to voltage converter is also called

(a) transconductance amplifier

(b) transimpedance amplifier

(c) transresistance amplifier


8.A VI op-amp converter is also called

(a) transconductance amplifier

(b) transresistance amplifier

(c) transimpedance amplifier


9.The differential mode and common mode voltage is defined as

(a) VDM = V2 − V1, VCM = V1 + V2/2

(b) VDM = V1 + V2/2, VCM = V2 − V1

(c) VDM = V1/2 = V2/2, VCM = V2 − V1/2


10.For a true difference amplifier, the following holds true:

(a) Acm → 0, CMRRdB → 0

(b) Acm →∞, CMRRdB →∞

(c) Acm →∞, CMRRdB → 0

(d) Acm →∞ 0, CMRRdB →∞

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

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 106 mΩ

(b) 106 mΩ to 1012 mΩ

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


16.Which of the following amplifier compensates for drift?

(a) Low gain amplifier

(b) High gain amplifier

(c) DC amplifier

(d) Differential amplifier

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


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


21.Noise in op-amp can be reduced to

(a) shielding

(b) uselpf

(c) proper grounding


22.An op-amp is generally not used as

(a) summer

(b) differentiator

(c) subtractor

(d) integrator

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


27.An integrator is mostly preferred over differentiator because

(a) more stable

(b) less voltage drift

(c) less noise


28.A chip having more than 150 logic gates is known as

(a) LSI chip

(b) MSI chip

(c) SSI chip


29.If a square wave is integrated by integrator using operational

amplifier, the output is

(a) triangular wave

(b) ramp

(c) sine wave


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

31.A good op-amp has

(a) very high bandwidth

(b) narrow bandwidth

(c) high selectivity


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

33.Which amplifier will be preferred for highest gain?

(a) darlington's pair

(b) operational amplifier

(c) cascade amplifier


34.Decibel is defined in terms of

(a) voltage ratio

(b) current ratio

(c) power ratio


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


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


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


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


42.Photolithography involves

(a) making photographic mask and photoetching

(b) onlyphotoetching

(c) only masking


43.Aluminium is generally used of metallization

(a) good mechanical bonds with silicon

(b) relatively good conductor

(c) depositaluminium films on the surface


44.The standard package configurations of manufacturing IC.

(a) glass metal package

(b) ceramic flat package

(c) dual in line


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.

47.The preference of polysilicon over aluminium

(a) lowers threshold voltage

(b) reduces capacitances

(c) good bond and mechanical strength, a form of silicon


48.The CMRR of MA 741 is

(a) 70 db

(b) 50 db

(c) 40 db


49.The common mode gain and differential mode gain of op-amp. is

(a) ADM = A1 − A2/2, ACM = A1 + A2

(b) ADM = A1 − A2, ACM = A1 + A2/2

(c) ADM = A1 + A2/2, ACM = A1 − A2

(d) ADM = A1/2 − A2/2 ACM = A1 − A2/2

50.The basic elements of op-amp is

(a) differential amplifier

(b) buffer, level translator

(c) output driver


51.For large CMRR, ACM should be

(a) as large as possible

(b) as small as possible

(c) zero

(d) level to Adm

52.MOSFET op-amp is preferred over BJT, FET because

(a) high input resistance 1012 Ω

(b) low input current, 1PA

(c) high slew rate, 10 V/μS

(d) all the above

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


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


57.An ideal op-amp should have open loop gain

(a) around 90 dB constent over audio and Rf frequency

(b) less than 90 dB, varies on audio and Rf frequency

(c) 20 dB, constent audio and Rf frequency


58.The frequency response of op-amp includes

(a) magnitude character only

(b) phase character only

(c) both (a) and (b)


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


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

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