GATE ECE topic:bjt-mosfet-amplifiers PYQs & Answers — Page 2

Questions 11–20 of 33. Imported answers require independent review unless marked reviewed.

In the circuit shown below, the transistors

and

are biased in saturation. Their small signal transconductances are

and

respectively. Neglect body effect, channel length modulation and intrinsic device capacitances.

Diagram for Electronics and Communication Engineering question 51

Assuming that capacitor

is a short circuit for AC analysis, the exact magnitude of small signal voltage gain

is ______.

Your answerChoose one option.

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In the circuit shown below,

and

are bias voltages. Based on input and output impedances, the circuit behaves as a

Diagram for Electronics and Communication Engineering question 21

Your answerChoose one option.

voltage controlled voltage source.

voltage controlled current source.

current controlled voltage source.

current controlled current source.

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A cascade of common-source amplifiers in a unity gain feedback configuration oscillates when

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the closed loop gain is less than 1 and the phase shift is less than 180°.

the closed loop gain is greater than 1 and the phase shift is less than 180°.

the closed loop gain is less than 1 and the phase shift is greater than 180°.

the closed loop gain is greater than 1 and the phase shift is greater than 180°.

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In the circuit below, the voltage

is __________ V (rounded off to two decimal places).

Diagram for Electronics and Communication Engineering question 64

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Consider the circuit shown with an ideal long channel

MOSFET (enhancement-mode, substrate is connected to the source). The transistor is appropriately biased in the saturation region with

and

such that it acts as a linear amplifier.

is the small-signal ac input voltage.

and

represent the small-signal voltages at the nodes A and B, respectively. The value of

is ________ (rounded off to one decimal place).

Diagram for Electronics and Communication Engineering question 59

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In the circuit shown in the figure, the transistors

and

are operating in saturation. The channel length modulation coefficients of both the transistors are non-zero. The transconductance of the MOSFETs

and

are

and

, respectively, and the internal resistance of the MOSFETs

and

are

and

, respectively.

Diagram for Electronics and Communication Engineering question 8

Ignoring the body effect, the ac small signal voltage gain (

) of the circuit is

Your answerChoose one option.

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For the BJT in the amplifier shown below,

mV. Assume that BJT output resistance (

) is very high and the base current is negligible. The capacitors are also assumed to be short circuited at signal frequencies. The input

is direct coupled. The low frequency voltage gain

of the amplifier is

Diagram for Electronics and Communication Engineering question 35

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Using the incremental low frequency small-signal model of the MOS device, the Norton equivalent resistance of the following circuit is

Diagram for Electronics and Communication Engineering question 37

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In the voltage regulator shown below, V_i is the unregulated input at 15 V. Assume V_BE = 0.7 V and the base current is negligible for both the BJTs. If the regulated output V_O is 9 V, the value of R₂ is ______ Ω.

Diagram for Electronics and Communication Engineering question 44

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In the circuits shown, the threshold voltage of each nMOS transistor is 0.6 V. Ignoring the effect of channel length modulation and body bias, the values of Vout1 and Vout2, respectively, in volts, are

Diagram for Electronics and Communication Engineering question 40

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1.8 and 1.2

2.4 and 2.4

1.8 and 2.4

2.4 and 1.2

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GATE ECE topic:bjt-mosfet-amplifiers PYQs

Question 51

Question 21

Question 22

Question 64

Question 59

Question 8

Question 35

Question 37

Question 44

Question 40