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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 PYQ1999Analog CircuitsOp-amp CircuitsMCQ · 1 mark
The first dominant pole encountered in the frequency response of a compensated op - amp\text{op - amp} is approximately at
Official PYQ1999Analog CircuitsBJT and MOSFET AmplifiersMCQ · 1 mark
The early effect in a bipolar junction transistor is caused by
Official PYQ1999Networks, Signals and SystemsCircuit AnalysisMCQ · 1 mark
A 22-port network is shown in the given figure. The parameter h21h_{21} for this network can be given by
Official PYQ1999Networks, Signals and SystemsCircuit AnalysisMCQ · 1 mark
If [f(t)]=F(s)[f(t)]=\mathrm{F}(s), then [f(t−T)][f(t-\mathrm{T})] is equal to
Official PYQ1999Networks, Signals and SystemsDiscrete-time SignalsMCQ · 1 mark
The zz-transform F(z)\mathrm{F}(z) of the function f(nT)=a′′Tf(n \mathrm{T})=a^{\prime \prime T} is
Official PYQ1999ElectromagneticsPlane Waves and PropertiesMCQ · 1 mark
A plane wave propagating through a medium [εr=8,vr=2\left[\varepsilon_{\mathrm{r}}=8, v_{\mathrm{r}}=2\right., and σ=0]\left.\sigma=0\right] has its electric field given by E→=0.5X^e−(z/3)sin⁡(108t−βz)V/m\overrightarrow{\mathrm{E}}=0.5 \hat{\mathrm{X}} \mathrm{e}^{-(z / 3)} \sin \left(10^{8} t-\beta z\right) \mathrm{V} / \mathrm{m}. The wave impedance, in ohms is
Official PYQ1999ElectromagneticsTransmission LinesMCQ · 1 mark
In air, a lossless transmission line of length 50 cm50 \mathrm{~cm} with L=10  μH/m,C=40  pF/m\mathrm{L}=10 \; \mu \mathrm{H} / \mathrm{m}, \mathrm{C}=40 \; \mathrm{pF} / \mathrm{m} is operated at 25  MHz25 \; \mathrm{MHz}. Its electrical path length is
Official PYQ1999ElectromagneticsTransmission LinesMCQ · 1 mark
A trasmitting antenna radiates 251 W251 \mathrm{~W} isotropically. A receiving antenna, located 100 m100 \mathrm{~m} away from the transmitting antenna, has an effective aperture of 500 cm2500 \mathrm{~cm}^{2}. The total received by the antenna is
Official PYQ1999ElectromagneticsTransmission LinesMCQ · 1 mark
In a twin-wire transmission line in air, the adjacent voltage maxima are at 12.5 cm12.5 \mathrm{~cm} and 27.5 cm27.5 \mathrm{~cm}. The operating frequency is
Official PYQ1999CommunicationsDigital CommunicationsMCQ · 1 mark
Four independent messages have bandwidths of 100 Hz,200 Hz100 \mathrm{~Hz}, 200 \mathrm{~Hz}, and 400 Hz400 \mathrm{~Hz}, respectively. Each is sampled at the Nyquist rate, and the samples are time division multiplexed (TDM\text{TDM}) and transmitted. The transmitted sample rate (in Hz\mathrm{Hz} ) is
Official PYQ1999CommunicationsDigital CommunicationsMCQ · 1 mark
The input to a matched filter is given by s(t)={100sin⁡(2π×106t)0<1<10−4secotherwises(t) = \left\{\begin{matrix} 10\\ 0 \end{matrix}\right. \begin{array}{ll} \sin \left(2 \pi \times 10^{6} t\right) & 0<1<10^{-4} \mathrm{sec} \\ & \text{otherwise} \end{array} The peak amplitude of the filter output is
Official PYQ1999CommunicationsDigital CommunicationsMCQ · 1 mark
The peak-to-peak input to an 88-bit PCM\text{PCM} coder is 22 volts. The signal power-to-quantization noise power ratio (in dBd\text{B}) for an input of 0.5cos⁡(ωmt)0.5 \cos \left(\omega_{m} t\right) is
Official PYQ1999Networks, Signals and SystemsContinuous-time SignalsMCQ · 1 mark
The Nyquist sampling frequency (in Hz\mathrm{Hz} ) of a signal given by 6×104sin⁡c2(400t)∗106sin⁡c3(100t)6 \times 10^{4} \sin c^{2}(400 t)^{*} 10^{6} \sin c^{3}(100 t) is
Official PYQ1999Networks, Signals and SystemsDiscrete-time SignalsMCQ · 1 mark
The zz-transform of a signal is given by C(z)=1z−1(1−z−4)4(1−z−1)2C(z)=\frac{1 z^{-1}\left(1-z^{-4}\right)}{4\left(1-z^{-1}\right)^{2}} Its final value is
Official PYQ1999Control SystemsMCQ · 1 mark
For the system described by the state equation x=[0100010.512]x+[001]ux=\left[\begin{array}{ccc} 0 & 1 & 0 \\ 0 & 0 & 1 \\ 0.5 & 1 & 2 \end{array}\right] x+\left[\begin{array}{l} 0 \\ 0 \\ 1 \end{array}\right] u If the control signal uu is given by u=[−0.5−3−5]u=[-0.5-3-5] x+vx+v, then the eigenvalues of the closed-loop system will be
Official PYQ1999Control SystemsMCQ · 1 mark
Consider the points s1=−3+j4s_{1}=-3+j 4 and s2=−3−j2s_{2}=-3-j 2 in the ss-plane. Then, for a system with the open-loop Transfer function G(s)H(s)=K(s+1)4G(s) H(s)=\frac{K}{(s+1)^{4}}
Official PYQ1999Control SystemsMCQ · 1 mark
If the closed-loop transfer function T(s)T(s) of a unity negative feedback system is given by T(s)=an−1 s+an sn+n1sn−1+…+an−1s+an\mathrm{T}(\mathrm{s})=\frac{a_{n -1} \mathrm{~s}+a_{n}}{\mathrm{~s}^{n}+n_{1} s^{n-1}+\ldots+a_{n-1} s+a_{n}} then the steady state error for a unit ramp input is
Official PYQ1999Digital CircuitsComputer OrganizationMCQ · 1 mark
If CS=A15   A14  A13\text{CS}=\text{A}_{15} \; \text{ A}_{14} \; \text{A}_{13} is used as the chip select logic of a 4  K RAM4 \; \text{K RAM} in an 80858085 system, then its memory range will be
Official PYQ1999Digital CircuitsSequential CircuitsMCQ · 1 mark
The ripple counter shown in the given figure is works as a
Official PYQ1999Digital CircuitsCombinatorial CircuitsMCQ · 1 mark
For a binary half-subtractor having two inputs A\text{A} and B\text{B}, the correct set of logical expressions for the outputs D\text{D} ( = A\text{A} minus B\text{B} ) and X(=\text{X}(= borrow) are