48 + Mcqs in Analog circuits miscellaneous Page 1 McqOptions

1.	An 8 bit unipolar successive approximation register type ADC is used to convert 3.5V to digital equal output. The reference voltage is +5V. The output of ADC at end of 3rd clock pulse after the start of conversion is .......... .
A.	1010 0000
B.	1000 0000
C.	0000 0001
D.	0000 0011
Answer» B. 1000 0000

Discussion

2.	A 41 / 2 digit DMM has the error specification as: 0.2% of reading +10 counts. If a dc voltage of 100 V is read on its 200 V full scale, the maximum error that can be expected in the reading is
A.	0.1%
B.	0.2%
C.	0.3%
D.	0.4%
Answer» D. 0.4%

Discussion

3.	Two 8-bit ADCs, one of single slope integrating type and other of successive approximation type, take TA and TB times to convert 5 V analog input signal to equivalent digital output. If the input analog signal is reduced to 2.5V, the approximate time taken by the two ADCs will respectively, be
A.	T
B.	, T
Answer» B. , T

Discussion

4.	For a class B amplifier providing a 20 V peak signal to 16&ohm; load and a power supply of Vcc = 30 V, efficiency will be _____ % .
A.	52.3
B.	22.3
C.	52
D.	32.33
Answer» B. 22.3

Discussion

5.	If input signal ei applied to the OP-AMP of the circuit shown in the given figure is sinusoidal at maximum value 1 mV and of 1kHz frequency, then magnitude of the peak value of the output voltage waveform would be _________ mV .
A.	628
B.	28
C.	68
D.	128
Answer» B. 28

Discussion

6.	Of the four characteristic given below, what are major requirements for an instrument amplifier? P : high common mode rejection ratio Q : high input impedance R : high linearity S : high output impedance
A.	P, Q & R only
B.	P & R only
C.	P, Q & S only
D.	Q, R & S only
Answer» B. P & R only

Discussion

7.	An amplifier with mid-band gain \| A\| = 500 has negative feedback = 1 .If upper cut-off without100 feedback were at 60 Hz, then with feedback it would become _________ kHz .
A.	360
B.	40
C.	160
D.	180
Answer» B. 40

Discussion

8.	For a transistor, parameters are = 180 and VA = 150V, and it is biassed at ICQ = 2m A. If collector of the tansistor is connected to the base terminal, t hen small signal resistaance re = vce/ ic of this two-terminal device is ____ &ohm; .
A.	4.32
B.	6.43
C.	12.87
D.	None of the above
Answer» D. None of the above

Discussion

9.	A CE amplifier has a resistor RF connected between collector an d base RF = 40 k. RC = 4k. I f hfe = 50, r = 1 k, then output resistance R0 is _______ k&ohm; .
A.	33
B.	0.66
C.	6.6
D.	3.3
Answer» C. 6.6

Discussion

10.	If = 0.98, ICO = 6 A and I = 100 A for a transistor, then value of IC will be _______ mA
A.	15.2
B.	5.2
C.	2.2
D.	8.4
Answer» C. 2.2

Discussion

11.	For the circuit of the given figure with an ideal operational amplifier, maximum phase shift of the output Vout with reference to the input Vin is
A.	0
B.	90
C.	+ 90
D.	+ 180
Answer» E.

Discussion

12.	An op-amp is open-loop gain of 105 and open-loop upper cut-off frequency of 10 Hz. If this OP-AMP is connected as an amplifier with a closed-loop gain at 100, then new uper cut-off frequency will be
A.	10 Hz
B.	100 Hz
C.	10 kHz
D.	100 kHz
Answer» D. 100 kHz

Discussion

13.	Output voltage of an OP-AMP for input voltage of Vi1 = 150 V, Vi22 = 140 V if amplifier has a differential gain of Ad = 4000 and value of CMRR is 100, is
A.	45.8 mV
B.	40.006 mV
C.	10 V
D.	145 V
Answer» B. 40.006 mV

Discussion

14.	OPAMP used as a tuned amplifier has the tuned circuit connected
A.	across input
B.	across series impedance at the input
C.	across feedback impedance Z
D.
E.	across output
Answer» D.

Discussion

15.	An amplifier has an open loop gain of 100, an input impedance of 1k&ohm;, and an out put impedance of 100 &ohm;. If a feedback network with a feedback factor of 0.99 is connected in a voltage series feedback mode then new input and output impedances are (a) (b)(c)
A.	10 &ohm; and 1 &ohm;
B.	10 &ohm; and 10 k &ohm;
C.	100 k &ohm; and 1 &ohm;
D.	100 k&ohm; 10 k &ohm;
Answer» D. 100 k&ohm; 10 k &ohm;

Discussion

16.	A junction transistor operating at room temperature with IC = 2 mA, where (kT / q) = 20 mV and = 100. The values of parameter gm in mhos and r in ohm respectively are
A.	0.04 and 2500
B.	0.08 and 1250
C.	0.5 and 800
D.	0.08 and 5000
Answer» C. 0.5 and 800

Discussion

17.	If an npn transistor (with C = 0.3 pF) has a unity gain cut-off frequency fT of 400 MHz at a d.c. bias current Ic = 1 mA, then value of its C is approximately (VT = 26 mV)
A.	15
B.	30
C.	50
D.	96
Answer» B. 30

Discussion

18.	If an npn transistor has a beta cut-off frequency fB of 1MHz, and emitter short circuit low frequency current gain 0 of 200, then unity gain frequency fT and alpha cut off frequency f respectively are
A.	200 MHz, 201 MHz
B.	200 MHz, 199 MHz
C.	199 MHz, 200 MHz
D.	201 MHz, 200 MHz
Answer» B. 200 MHz, 199 MHz

Discussion

19.	In an FET as VGS is changed from zero to increasing reverse bias, the value of gm
A.	increased
B.	decreased
C.	remains constant
D.	falls suddenly to zero
Answer» C. remains constant

Discussion

20.	For a class B amplifier providing a 20 V peak signal to 16&ohm; load and a power supply of V
A.	52.3
B.	22.3
C.	52
D.	32.33
Answer» B. 22.3

Discussion

21.	A(0 50A) moving coil ammet er has a volt age dr op of 0.1V across its terminals at full scale deflection. The external shunt resistance (in milliohms) needed to extend its range to (0 500A) is ______.
A.	0.22 to 0.23
B.	0.21
C.	0.13
D.	0.21 to 0.22
Answer» B. 0.21

Discussion

22.	Output voltage of an OP-AMP for input voltage of V
A.	45.8 mV
B.	40.006 mV
C.	10 V
D.	145 V
Answer» B. 40.006 mV

Discussion

23.	A CE amplifier has a resistor R
A.	33
B.	0.66
C.	6.6
D.	3.3
Answer» C. 6.6

Discussion

24.	If = 0.98, I
A.	15.2
B.	5.2
C.	2.2
D.	8.4
Answer» C. 2.2

Discussion

25.	An amplifier with mid-band gain \| A\| = 500 has negative feedback = 1 .If upper cut-off without100
A.	360
B.	40
C.	160
D.	180
Answer» B. 40

Discussion

26.	A constant current signal across a parallel RLC circuit gives an output of 1.4 volts at the signal frequency of 3.89 k Hz and 4.1 kHz. At frequency of 4k Hz, out put voltage will be __________ V
A.	1
B.	2
C.	3
D.	4
Answer» C. 3

Discussion

27.	When a bipolar junction transistor is operating in the saturation mode, which one of the following statement is TRUE about the state of its collectorbase (CB) and the base-emitter (BE) junctions?
A.	The CB junction is forward biased and the BE junction is reverse biased.
B.	The CB junction is reversed and t he BE junction is forward biased.
C.	Both the CB and BE junctions are forward biased.
D.	Both the CB and BE junctions are reverse biased.
Answer» D. Both the CB and BE junctions are reverse biased.

Discussion

28.	An 8 bit unipolar successive approximation register type ADC is used to convert 3.5V to digital equal output. The reference voltage is +5V. The output of ADC at end of 3
A.	1010 0000
B.	1000 0000
C.	0000 0001
D.	0000 0011
Answer» B. 1000 0000

Discussion

29.	If an amplifier with gain of 1000 and feedback of b = 0.1 had a gain change of 20% due to temperature, then change in gain of the feedback amplifier would be __________ % .
A.	0.002%
B.	0.2%
C.	2%
D.	2.2%
Answer» C. 2%

Discussion

30.	For a transistor, parameters are = 180 and V
A.	4.32
B.	6.43
C.	12.87
D.	None of the above
Answer» D. None of the above

Discussion

31.	An op-amp, having a slew rate of 62.8 V/msec, is connected in a voltage follower configuration. If maximum amplitude of the input sinusoid is 10 V, then minimum frequency at which slew rate limited distortion would set in at the output is _________ MHz
A.	1
B.	2
C.	3
D.	4
Answer» B. 2

Discussion

32.	Of the four characteristic given below, what are major requirements for an instrument amplifier?
A.	P, Q & R only
B.	P & R only
C.	P, Q & S only
D.	Q, R & S only
Answer» B. P & R only

Discussion

33.	If input signal e
A.	628
B.	28
C.	68
D.	128
Answer» B. 28

Discussion

34.	For the circuit of the given figure with an ideal operational amplifier, maximum phase shift of the output V
A.	0
B.	90
C.	+ 90
D.	+ 180
Answer» E.

Discussion

35.	An op-amp is open-loop gain of 10
A.	10 Hz
B.	100 Hz
C.	10 kHz
D.	100 kHz
Answer» D. 100 kHz

Discussion

36.	If differential amplifier has a differential gain of 20,000. CMRR = 80 dB, then common mode gain is
A.	2
B.	1
C.	1 / 2
D.	0
Answer» B. 1

Discussion

37.	In a common emitter amplifier, the unbypassed emitter resistance provides
A.	voltage-shunt feedback
B.	current-series feedback
C.	negative-voltage feedback
D.	positive-current feedback
Answer» D. positive-current feedback

Discussion

38.	If an amplifier with resistive negative feedback has two left half planes poles in its open-loop transfer function then amplifier
A.	will always be unstable at high frequencies.
B.	will be stable for all frequncies.
C.	may be unstable, depending upon the feedback factor.
D.	will oscillate at low frequencies.
Answer» C. may be unstable, depending upon the feedback factor.

Discussion

39.	An amplifier has an open loop gain of 100, an input impedance of 1k&ohm;, and an out put impedance of 100 &ohm;. If a feedback network with a feedback factor of 0.99 is connected in a voltage series feedback mode then new input and output impedances are
A.	10 &ohm; and 1 &ohm;
B.	10 &ohm; and 10 k &ohm;
C.	100 k &ohm; and 1 &ohm;
D.	100 k&ohm; 10 k &ohm;
Answer» D. 100 k&ohm; 10 k &ohm;

Discussion

40.	A junction transistor operating at room temperature with I
A.	0.04 and 2500
B.	0.08 and 1250
C.	0.5 and 800
D.	0.08 and 5000
Answer» C. 0.5 and 800

Discussion

41.	A signal may have frequency components which lie in the range of 0.001 Hz to 10Hz. which of the following types of coupling should be chosen in a multistage amplifier designed to amplify this signal ?
A.	RC coupling
B.	Transformer coupling
C.	Direct coupling
D.	Double-tuned coupling
Answer» D. Double-tuned coupling

Discussion

42.	If a two-stage amplifier is required to have an upper cut-off frequency of 2 MHz and a lower cut-off frequency of 30 Hz then upper and lower cut -off frequencies of individual st age are respectively
A.	4 MHz, 60 Hz
B.	3 MHz, 20 Hz
C.	3 MHz, 60 Hz
D.	4 MHz, 20 Hz
Answer» C. 3 MHz, 60 Hz

Discussion

43.	If an npn transistor (with C = 0.3 pF) has a unity gain cut-off frequency f
A.	15
B.	30
C.	50
D.	96
Answer» B. 30

Discussion

44.	If an npn transistor has a beta cut-off frequency f
A.	200 MHz, 201 MHz
B.	200 MHz, 199 MHz
C.	199 MHz, 200 MHz
D.	201 MHz, 200 MHz
Answer» B. 200 MHz, 199 MHz

Discussion

45.	The gain bandwidth product of a two stage CE amplifier is
A.	same as that of one stage
B.	greater than that of one stage
C.	less than that of one stage
D.	product of the two gain bandwidth products of each stage
Answer» B. greater than that of one stage

Discussion

46.	In an FET as V
A.	increased
B.	decreased
C.	remains constant
D.	falls suddenly to zero
Answer» C. remains constant

Discussion

47.	The threshold voltage of an n-channel MOSFET can be increased by
A.	increasing channel doping concentration
B.	reducing channel length
C.	reducing gate oxide thickness
D.	decreasing channel doping concentration
Answer» C. reducing gate oxide thickness

Discussion

48.	The MOSFET swit ch in it s on-st at e may be considered equivalent to
A.	resistor
B.	inductor
C.	capacitor
D.	battery
Answer» D. battery

Discussion

Explore topic-wise MCQs in Analog Circuits.

An 8 bit unipolar successive approximation register type ADC is used to convert 3.5V to digital equal output. The reference voltage is +5V. The output of ADC at end of 3rd clock pulse after the start of conversion is .......... .

A 41 / 2 digit DMM has the error specification as: 0.2% of reading +10 counts. If a dc voltage of 100 V is read on its 200 V full scale, the maximum error that can be expected in the reading is

Two 8-bit ADCs, one of single slope integrating type and other of successive approximation type, take TA and TB times to convert 5 V analog input signal to equivalent digital output. If the input analog signal is reduced to 2.5V, the approximate time taken by the two ADCs will respectively, be

For a class B amplifier providing a 20 V peak signal to 16&ohm; load and a power supply of Vcc = 30 V, efficiency will be _____ % .

If input signal ei applied to the OP-AMP of the circuit shown in the given figure is sinusoidal at maximum value 1 mV and of 1kHz frequency, then magnitude of the peak value of the output voltage waveform would be _________ mV .

Of the four characteristic given below, what are major requirements for an instrument amplifier? P : high common mode rejection ratio Q : high input impedance R : high linearity S : high output impedance

An amplifier with mid-band gain | A| = 500 has negative feedback = 1 .If upper cut-off without100 feedback were at 60 Hz, then with feedback it would become _________ kHz .

For a transistor, parameters are = 180 and VA = 150V, and it is biassed at ICQ = 2m A. If collector of the tansistor is connected to the base terminal, t hen small signal resistaance re = vce/ ic of this two-terminal device is ____ &ohm; .

A CE amplifier has a resistor RF connected between collector an d base RF = 40 k. RC = 4k. I f hfe = 50, r = 1 k, then output resistance R0 is _______ k&ohm; .

If = 0.98, ICO = 6 A and I = 100 A for a transistor, then value of IC will be _______ mA

For the circuit of the given figure with an ideal operational amplifier, maximum phase shift of the output Vout with reference to the input Vin is

An op-amp is open-loop gain of 105 and open-loop upper cut-off frequency of 10 Hz. If this OP-AMP is connected as an amplifier with a closed-loop gain at 100, then new uper cut-off frequency will be

Output voltage of an OP-AMP for input voltage of Vi1 = 150 V, Vi22 = 140 V if amplifier has a differential gain of Ad = 4000 and value of CMRR is 100, is

OPAMP used as a tuned amplifier has the tuned circuit connected

An amplifier has an open loop gain of 100, an input impedance of 1k&ohm;, and an out put impedance of 100 &ohm;. If a feedback network with a feedback factor of 0.99 is connected in a voltage series feedback mode then new input and output impedances are (a) (b)(c)

A junction transistor operating at room temperature with IC = 2 mA, where (kT / q) = 20 mV and = 100. The values of parameter gm in mhos and r in ohm respectively are

If an npn transistor (with C = 0.3 pF) has a unity gain cut-off frequency fT of 400 MHz at a d.c. bias current Ic = 1 mA, then value of its C is approximately (VT = 26 mV)

If an npn transistor has a beta cut-off frequency fB of 1MHz, and emitter short circuit low frequency current gain 0 of 200, then unity gain frequency fT and alpha cut off frequency f respectively are

In an FET as VGS is changed from zero to increasing reverse bias, the value of gm

For a class B amplifier providing a 20 V peak signal to 16&ohm; load and a power supply of V

A(0 50A) moving coil ammet er has a volt age dr op of 0.1V across its terminals at full scale deflection. The external shunt resistance (in milliohms) needed to extend its range to (0 500A) is ______.

Output voltage of an OP-AMP for input voltage of V

A CE amplifier has a resistor R

If = 0.98, I

An amplifier with mid-band gain | A| = 500 has negative feedback = 1 .If upper cut-off without100

A constant current signal across a parallel RLC circuit gives an output of 1.4 volts at the signal frequency of 3.89 k Hz and 4.1 kHz. At frequency of 4k Hz, out put voltage will be __________ V

When a bipolar junction transistor is operating in the saturation mode, which one of the following statement is TRUE about the state of its collectorbase (CB) and the base-emitter (BE) junctions?

An 8 bit unipolar successive approximation register type ADC is used to convert 3.5V to digital equal output. The reference voltage is +5V. The output of ADC at end of 3

If an amplifier with gain of 1000 and feedback of b = 0.1 had a gain change of 20% due to temperature, then change in gain of the feedback amplifier would be __________ % .

For a transistor, parameters are = 180 and V

An op-amp, having a slew rate of 62.8 V/msec, is connected in a voltage follower configuration. If maximum amplitude of the input sinusoid is 10 V, then minimum frequency at which slew rate limited distortion would set in at the output is _________ MHz

Of the four characteristic given below, what are major requirements for an instrument amplifier?

If input signal e

For the circuit of the given figure with an ideal operational amplifier, maximum phase shift of the output V

An op-amp is open-loop gain of 10

If differential amplifier has a differential gain of 20,000. CMRR = 80 dB, then common mode gain is

In a common emitter amplifier, the unbypassed emitter resistance provides

If an amplifier with resistive negative feedback has two left half planes poles in its open-loop transfer function then amplifier

An amplifier has an open loop gain of 100, an input impedance of 1k&ohm;, and an out put impedance of 100 &ohm;. If a feedback network with a feedback factor of 0.99 is connected in a voltage series feedback mode then new input and output impedances are

A junction transistor operating at room temperature with I

A signal may have frequency components which lie in the range of 0.001 Hz to 10Hz. which of the following types of coupling should be chosen in a multistage amplifier designed to amplify this signal ?

If a two-stage amplifier is required to have an upper cut-off frequency of 2 MHz and a lower cut-off frequency of 30 Hz then upper and lower cut -off frequencies of individual st age are respectively

If an npn transistor (with C = 0.3 pF) has a unity gain cut-off frequency f

If an npn transistor has a beta cut-off frequency f

The gain bandwidth product of a two stage CE amplifier is

In an FET as V

The threshold voltage of an n-channel MOSFET can be increased by

The MOSFET swit ch in it s on-st at e may be considered equivalent to