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GATE EC question library

Practise GATE EC Electronics and Communication previous year questions free. Browse by subject, syllabus topic, year and question type, with answers and available solutions.

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Official PYQ2019Electronic DevicesMCQ · 1 mark
What is the electric flux (∫E⃗.da^)\left(\int \vec{E}.d \hat{a}\right) through a quarter-cylinder of height HH (as shown in the figure) due to an infinitely long line charge along the axis of the cylinder with a charge density of Q?Q?
Official PYQ2019ElectromagneticsMaxwell's EquationsMCQ · 1 mark
In the table shown, List I and List II, respectively, contain terms appearing on the left-hand side and the right-hand side of Maxwell’s equations (in their standard form). Match the left-hand side with the corresponding right-hand side. …
Official PYQ2019Electronic DevicesMCQ · 1 mark
A standard CMOS inverter is designed with equal rise and fall times (βn=βp).(\beta_{n}=\beta_{p}). If the width of the pMOS transistor in the inverter is increased, what would be the effect on the LOW noise margin NMLNM_{L} and the HIGH noise margin NMHNM_{H}?
Official PYQ2019Digital CircuitsCombinatorial CircuitsMCQ · 1 mark
In the circuit shown, what are the values of FF for EN=0EN=0 and EN=1,EN=1, respectively?
Official PYQ2019Digital CircuitsSemiconductor MemoriesMCQ · 1 mark
In the circuit shown, AA and BB are the inputs and FF is the output. What is the functionality of the circuit?
Official PYQ2019Engineering MathematicsComplex AnalysisNAT · 1 mark
The value of the contour integral 12πj∮(z+1z)2dz\frac{1}{2\pi j} \oint\left(z+\frac{1}{z}\right)^{2}dz evaluated over the unit circle ∣z∣=1\mid z \mid=1 is_______.
Official PYQ2019Engineering MathematicsLinear AlgebraNAT · 1 mark
The number of distinct eigenvalues of the matrix A=[2233011100330002]A=\begin{bmatrix} 2&2&3&3\\0&1&1&1\\0&0&3&3\\0&0&0&2 \end{bmatrix} is equal to ____________.
Official PYQ2019Engineering MathematicsProbability and StatisticsNAT · 1 mark
If XX and YY are random variables such that E[2X+Y]=0E\left[2X+Y\right]=0 and E[X+2Y]=33E\left[X+2Y\right]=33, then E[X]+E[Y]=E\left[X\right]+E\left[Y\right]=___________.
Official PYQ2019Engineering MathematicsCalculusNAT · 1 mark
The value of the integral ∫0π∫yπsin⁡xxdx dy,\displaystyle{}\int_{0}^{\pi} \int_{y}^{\pi}\dfrac{\sin x}{x}dx\: dy , is equal to __________.
Official PYQ2019Engineering MathematicsProbability and StatisticsNAT · 1 mark
Let ZZ be an exponential random variable with mean 11. That is, the cumulative distribution function of ZZ is given by FZ(x)={1−e−xif x≥00if x<0F_{Z}(x)= \left\{\begin{matrix} 1-e^{-x}& \text{if}\: x \geq 0 \\ 0& \text{if}\: x< 0 \end{matrix}\right. Then Pr(Z>2∣Z>1),Pr\left(Z>2 \mid Z>1\right), rounded off to two decimal places, is equal to ___________.
Official PYQ2019Networks, Signals and SystemsContinuous-time SignalsNAT · 1 mark
Consider the signal f(t)=1+2cos⁡(πt)+3sin⁡(2π3t)+4cos⁡(π2t+π4)f(t)=1+2 \cos(\pi t)+3 \sin \left(\dfrac{2\pi}{3}t\right)+4 \cos \left(\dfrac{\pi}{2}t+\dfrac{\pi}{4}\right), where tt is in seconds. Its fundamental time period, in seconds, is __________.
Official PYQ2019Networks, Signals and SystemsContinuous-time SignalsNAT · 1 mark
The baseband signal m(t)m(t) shown in the figure is phase-modulated to generate the PMPM signal φ(t)=cos⁡(2πfct+k  m(t)).\varphi(t)=\cos(2\pi f_{c}t+ k\:\: m(t)). The time tt on the x−x- axis in the figure is in milliseconds. If the carrier frequency is fc=50 kHzf_{c}=50\:kHz and k=10π,k=10 \pi, then the ratio of the minimum instantaneous frequency (in kHz) to the maximum …
Official PYQ2019ElectromagneticsTransmission LinesNAT · 1 mark
Radiation resistance of a small dipole current element of length ll at a frequency of 33 GHz is 33 ohms. If the length is changed by 1%1\%, then the percentage change in the radiation resistance, rounded off to two decimal places, is ________ %.\%.
Official PYQ2019ElectromagneticsMaxwell's EquationsNAT · 1 mark
In the circuit shown, VsV_{s} is square wave of period TT with maximum and minimum values of 8 V8\: V and −10 V-10\: V, respectively. Assume that the diode is ideal and R1=R2=50 Ω.R_{1}=R_{2}=50\: \Omega. The average value of VLV_{L} is _______ volts (rounded off to 11 decimal place).
Official PYQ2019Networks, Signals and SystemsContinuous-time SignalsNAT · 1 mark
In the circuit shown, the clock frequency, i.e., the frequency of the ClK signal, is 12 kHz12\:kHz. The frequency of the signal at Q2Q_{2} is _______ kHz.
Official PYQ2019Engineering MathematicsCalculusMCQ · 2 marks
Consider a differentiable function f(x)f(x) on the set of real numbers, such that f(−1)=0f(-1)=0 and ∣f’(x)∣≤2.\mid f’(x) \mid \leq 2. Given these conditions, which one of the following inequalities is necessarily true for all x∈[−2,2]?x \in[-2,2]?
Official PYQ2019Engineering MathematicsVector AnalysisMCQ · 2 marks
Consider the line integral ∫c(xdy−ydx)\int_{c} (xdy-ydx) the integral being taken in a counterclockwise direction over the closed curve CC that forms the boundary of the region RR shown in the figure below. The region RR is the area enclosed by the union of a 2×32 \times 3 rectangle and a semi-circle of radius 11. The line integral evaluates to
Official PYQ2019Networks, Signals and SystemsDiscrete-time SignalsMCQ · 2 marks
Consider a six-point decimation-in-time Fast Fourier Transform (FFT)(FFT) algorithm, for which the signal-flow graph corresponding to X[1]X[1] is shown in the figure. Let W6=exp(− j2π6).W_{6}=exp\left(-\:\dfrac{j2\pi}{6}\right). In the figure, what should be the values of the coefficients a1,a2,a3a_{1},a_{2},a_{3} in terms of W6W_{6} so that X[1]X[1] is obtained …
Official PYQ2019Control SystemsMCQ · 2 marks
It is desired to find a three-tap casual filter which gives zero signal as an output to an input of the form x[n]=c1exp(−jπn2)+c2(jπn2),x[n]= c_{1}exp\left(-\dfrac{j\pi n}{2}\right)+c_{2}\left(\dfrac{j\pi n}{2}\right), where c1c_{1} and c2c_{2} are arbitrary real numbers. The desired three-tap filter is given by h[0]=1,h[1]=a,h[2]=bh[0]=1,\quad h[1]=a,\quad h[2]=b and …
Official PYQ2019Networks, Signals and SystemsCircuit AnalysisMCQ · 2 marks
In the circuit shown, if v(t)=2sin⁡(1000 t)v(t)=2 \sin(1000\: t) volts, R=1 kΩR=1\:k \Omega and C=1 μF,C=1\:\mu F, then the steady-state current i(t)i(t), milliamperes (mA), is