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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 PYQ2012Networks, Signals and SystemsContinuous-time SignalsMCQ · 2 marks
The Fourier transform of a signal h(t)h(t) is H(jω)=(2cos⁡ω)(sin⁡2ω)/ωH(j\omega)=(2\cos\omega)(\sin2\omega)/\omega. The value of h(0)h(0) is
Official PYQ2012Networks, Signals and SystemsLTI SystemsMCQ · 2 marks
The state variable description of an LTI system is given by (x1˙x2˙x3˙)=(0a1000a2a300)(x1x2x3)+(001)u\begin{pmatrix} \dot{x_1}\\ \dot{x_2}\\ \dot{x_3} \end{pmatrix}=\begin{pmatrix} 0 & a_1 & 0\\ 0 & 0 & a_2\\a_3 & 0 & 0 \end{pmatrix} \begin{pmatrix} x_1\\ x_2\\x_3 \end{pmatrix}+\begin{pmatrix} 0\\ 0\\1 \end{pmatrix}u …
Official PYQ2012Analog CircuitsOp-amp CircuitsMCQ · 2 marks
Assuming both the voltage sources are in phase, the value of RR for which maximum power is transferred from circuit AA to circuit BB is
Official PYQ2012Engineering MathematicsDifferential EquationsMCQ · 2 marks
Consider the differential equation d2y(t)dt2+2dy(t)dt+y(t)=δ(t)\frac{d^2y(t)}{dt^2}+2\frac{dy(t)}{dt}+y(t)=\delta(t) with y(t)∣t=0−=−2y(t)\big|_{t=0^-}=-2 and dydt∣t=0−=0\frac{dy}{dt}\big|_{t=0^-}=0. The numerical value of dydt∣t=0+\frac{dy}{dt}\big|_{t=0^+} is
Official PYQ2012Engineering MathematicsVector AnalysisMCQ · 2 marks
The direction of vector AA is radially outward from the origin, with ∣A∣=krn|A|=kr^n where r2=x2+y2+z2r^2=x^2+y^2+z^2 and kk is a constant. The value of nn for which ▽.A=0\triangledown.A=0 is
Official PYQ2012Engineering MathematicsProbability and StatisticsMCQ · 2 marks
A fair coin is tossed till head appears for the first time. The probability that the number of required tosses is odd, is
Official PYQ2012Electronic DevicesMCQ · 2 marks
In the CMOS circuit shown, electron and hole mobilities are equal, and M1M1 and M2M2 are equally sized. The device M1M1 is in the linear region if
Official PYQ2012Engineering MathematicsProbability and StatisticsMCQ · 2 marks
A binary symmetric channel (BSC) has a transition probability of 18\frac{1}{8}. If the binary transmit symbol XX is such that P(X=0) = 910P(X=0)\:=\:\frac{9}{10}, then the probability of error for an optimum receiver will be
Official PYQ2012CommunicationsAnalog CommunicationsMCQ · 2 marks
The signal m(t)m(t) as shown is applied both to a phase modulator (with kpk_p as the phase constant) and a frequency modulator (with kfk_f as the frequency constant) having the same carrier frequency. The ratio kpkf\frac{k_p}{k_f} (in rad/Hzrad/Hz) for the same maximum phase deviation is
Official PYQ2012ElectromagneticsTransmission LinesMCQ · 2 marks
The magnetic field along the propagation direction inside a rectangular waveguide with the cross-section shown in the figure is HZ=3 cos⁡(2.094×102x) cos⁡(2.618×102y) cos⁡(6.283×1010t−βz)H_Z=3\:\cos(2.094\times10^2x)\:\cos(2.618\times10^2y)\:\cos(6.283\times10^{10}t-\beta z) The phase velocity vpv_p of the wave inside the waveguide satisfies
Official PYQ2012Networks, Signals and SystemsCircuit AnalysisMCQ · 2 marks
The circuit shown is a
Official PYQ2012Networks, Signals and SystemsLTI SystemsMCQ · 2 marks
Let y[n]y[n] denote the convolution of h[n]h[n] and g[n]g[n], where h[n]=(12)nu[n]h[n]=(\frac{1}{2})^nu[n] and g[n]g[n] is a casual sequence. If y[0]=1y[0]=1 and y[1]=12y[1]=\frac{1}{2}, then g[1]g[1] equals
Official PYQ2012Digital CircuitsSequential CircuitsMCQ · 2 marks
The state transition diagram for the logic circuit shown is
Official PYQ2012Analog CircuitsBJT and MOSFET AmplifiersMCQ · 2 marks
The voltage gain AvA_v of the circuit shown below is
Official PYQ2012Networks, Signals and SystemsCircuit AnalysisMCQ · 2 marks
If VA−VB=6 VV_A-V_B=6\:V, then VC−VDV_C-V_D is
Official PYQ2012Engineering MathematicsCalculusMCQ · 2 marks
The maximum value of f(x)=x3−9x2+24x+5f(x)=x^3-9x^2+24x+5 in the interval [1,6][1,6] is
Official PYQ2012Engineering MathematicsLinear AlgebraMCQ · 2 marks
Given that A=[−5−320]A=\begin{bmatrix} -5 &-3 \\ 2 &0\end{bmatrix} and I=[1001]I=\begin{bmatrix} 1 & 0 \\ 0 &1\end{bmatrix}, the value of A3A^3 is
Official PYQ2012Networks, Signals and SystemsCircuit AnalysisMCQ · 2 marks
With 10 V10\:V dc connected at port A in the linear nonreciprocal two-port network shown below, the following were observed: 1 Ω1\: \Omega connected at port B draws a current of 3 A3\:A 2.5 Ω2.5\: \Omega connected at port B draws a current of 2 A2\:A With 10 V10\: V dc connected at port A, the current drawn by 7 Ω7\:\Omega connected at port B is
Official PYQ2012Networks, Signals and SystemsCircuit AnalysisMCQ · 2 marks
With 10 V10\:V dc connected at port A in the linear nonreciprocal two-port network shown below, the following were observed: 1 Ω1\: \Omega connected at port B draws a current of 3 A3\:A 2.5 Ω2.5\: \Omega connected at port B draws a current of 2 A2\:A For the same network, with 6 V6\: V dc connected at port A, 1 Ω1\:\Omega connected at port B draws …
Official PYQ2012Analog CircuitsBJT and MOSFET AmplifiersMCQ · 2 marks
In the three dimensional view of a silicon n-channel MOS transistor shown below, δ=20 nm\delta=20\:nm. The transistor is of width 1 μm1\: \mu m. The depletion width formed at every p-n junction is 10 nm10\:nm. The relative permittivities of SiSi and SiO2SiO_2, respectively, are 11.711.7 and 3.93.9, and ε0=8.9×10−12 F/m\varepsilon_0=8.9 \times 10^{-12} \: F/m. The …