Electronics and Communication Engineering
GATE ECE format:mcq PYQs
Build your understanding with focused practice from past exam papers.
Questions 71–80 of 426. Imported answers require independent review unless marked reviewed.
Question 40
Open questionECMCQ2 marksNeeds review
The
-parameter matrix of a two port network relates the port voltages and port currents as follows:
The
-parameter matrix (with each entry in Ohms) of the network shown below is ________. 
Your answerChoose one option.
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Open questionECMCQ2 marksNeeds review
A source transmits symbol
that takes values uniformly at random from the set
. The receiver obtains
, where
is a zero-mean Gaussian random variable independent of
. The receiver uses the maximum likelihood decoder to estimate the transmitted symbol
.Suppose the probability of symbol estimation error
is expressed as follows:
where
denotes the probability that
exceeds 1.What is the value of
?Your answerChoose one option.
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 42
Open questionECMCQ2 marksNeeds review
Consider a real-valued random process
where
and
is a positive integer. Here,
for
and 0 otherwise. The coefficients
are pairwise independent, zero-mean unit-variance random variables.Read the following statements about the random process and choose the correct option.
(i) The mean of the process
is independent of time
.(ii) The autocorrelation function
is independent of time
for all
.(Here,
is the expectation operation.)Your answerChoose one option.
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 43
Open questionECMCQ2 marksNeeds review
The identical MOSFETs M₁ and M₂ in the circuit given below are ideal and biased in the saturation region. M₁ and M₂ have a transconductance
of 5 mS.The input signals (in Volts) are:
The output signal
(in Volts) is ________. 
Your answerChoose one option.
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Open questionECMCQ2 marksNeeds review
A 10-bit analog-to-digital converter (ADC) has a sampling frequency of 1 MHz and a full scale voltage of 3.3 V.
For an input sinusoidal signal with frequency 500 kHz, the maximum SNR (in dB, rounded off to two decimal places) and the data rate (in Mbps) at the output of the ADC are ________, respectively.
Your answerChoose one option.
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 45
Open questionECMCQ2 marksNeeds review
A positive-edge-triggered sequential circuit is shown below. There are no timing violations in the circuit. Input P0 is set to logic ‘0’ and P1 is set to logic ‘1’ at all times. The timing diagram of the inputs SEL and S are also shown below.
The sequence of output Y from time T₀ to T₃ is ________.
Your answerChoose one option.
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Open questionECMCQ2 marksNeeds review
The intrinsic carrier concentration of a semiconductor is 2.5 × 10¹⁶ /m³ at 300 K. If the electron and hole mobilities are 0.15 m²/Vs and 0.05 m²/Vs, respectively, then the intrinsic resistivity of the semiconductor (in kΩ.m) at 300 K is ______.
(Charge of an electron e = 1.6 × 10⁻¹⁹ C.)
Your answerChoose one option.
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Open questionECMCQ2 marksNeeds review
In the circuit shown, the identical transistors Q1 and Q2 are biased in the active region with β = 120. The Zener diode is in the breakdown region with VZ = 5 V and IZ = 25 mA.
If IL = 12 mA and VEB1 = VEB2 = 0.7 V, then the values of R1 and R2 (in kΩ, rounded off to one decimal place) are ______, respectively.
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Open questionECMCQ2 marksNeeds review
The electron mobility μₙ in a non-degenerate germanium semiconductor at 300 K is 0.38 m²/Vs.
The electron diffusivity Dₙ at 300 K (in cm²/s, rounded off to the nearest integer) is ______.
(Consider the Boltzmann constant kB = 1.38 × 10⁻²³ J/K and the charge of an electron e = 1.6 × 10⁻¹⁹ C.)
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 49
Open questionECMCQ2 marksNeeds review
A square metal sheet of
is placed on the
-
plane as shown in the figure below.If the surface charge density (in
) on the sheet is
, then the total charge (in
, rounded off to the nearest integer) on the sheet is ______.
Your answerChoose one option.
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