Skip to content

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.

Subject, topic, year and type filter the full library. Match any choice within a filter, and all selected filter categories. Search, source and sort apply to this page.

20 on this page
Official PYQ2015ElectromagneticsPlane Waves and PropertiesMCQ · 1 mark
The polar plot of the transfer function G(s)=10(s+1)s+10G(s) = \frac{10(s+1)}{s+10} for 0≤ω<∞0 \leq \omega < \infty will be in the
Official PYQ2015Networks, Signals and SystemsContinuous-time SignalsMCQ · 1 mark
A sinusoidal signal of 22 kHz frequency is applied to a delta modulator. The sampling rate and step-size Δ\Delta of the data modulator are 20,00020,000 samples per second and 0.10.1 V, respectively. To prevent slope overload, the maximum amplitude of the sinusoidal signal (in Volts) is
Official PYQ2015Networks, Signals and SystemsContinuous-time SignalsMCQ · 1 mark
Consider the signal s(t)=m(t)cos⁡(2π fct)+m^(t)sin⁡(2πfct)s(t)=m(t) \cos(2 \pi \: f_ct)+ \hat{m}(t) \sin(2 \pi f_c t) where m^(t)\hat{m}(t) denotes the Hilbert transform of m(t)m(t) and the bandwidth of m(t)m(t) is very small compared to fcf_c. The signal s(t)s(t) is a
Official PYQ2015Electronic DevicesMCQ · 1 mark
Consider a straight, infinitely long, current carrying conductor lying on the z-axis. Which one of the following plots (in linear scale) qualitatively represents the dependence of HϕH_{\phi} on rr, where HϕH_{\phi} is the magnitude of the azimuthal component of magnetic field outside the conductor and rr is the radial distance from the conductor?
Official PYQ2015ElectromagneticsPlane Waves and PropertiesNAT · 1 mark
The electric field component of a plane wave traveling in a lossless dielectric medium is given by E→(z,t)=a^y2cos⁡(10st−z2) V/m\overrightarrow{E}(z,t) = \hat{a}_y 2 \cos \bigg( 10^st-\frac{z}{\sqrt{2}} \bigg) \: V/m. The wavelength (in m) for the wave is ___________.
Official PYQ2015Engineering MathematicsDifferential EquationsMCQ · 2 marks
The solution of the differential equation d2ydt2+2dydt+y=0\frac{d^2y}{dt^2} + 2 \frac{dy}{dt}+y=0 with y(0)=y’(0)=1y(0)=y’(0)=1 is
Official PYQ2015Engineering MathematicsVector AnalysisMCQ · 2 marks
A vector P→\overrightarrow{P} is given by P→=x3ya→x–x2y2a→y–x2yza→z\overrightarrow{P} = x^3y\overrightarrow{a}_x – x^2y^2\overrightarrow{a}_y – x^2 yz \overrightarrow{a}_z. Which one of the statements is TRUE?
Official PYQ2015Engineering MathematicsCalculusMCQ · 2 marks
Which one of the following graphs describes the function f(x)=e−x(x2+x+1)f(x)=e^{-x}(x^2+x+1)?
Official PYQ2015Engineering MathematicsCalculusNAT · 2 marks
The maximum area (in square units) of a rectangle whose vertices lie on the eclipse x2+4y2=1x^2+4y^2=1 is __________.
Official PYQ2015Networks, Signals and SystemsCircuit AnalysisMCQ · 2 marks
The damping ratio of a series RLC circuit can be expressed as
Official PYQ2015Networks, Signals and SystemsCircuit AnalysisNAT · 2 marks
In the circuit shown, switch SW is closed at t=0t=0. Assuming zero initial conditions, the value of vc(t)v_c(t) (in Volts) at t=1t=1 sec is _________.
Official PYQ2015Networks, Signals and SystemsCircuit AnalysisNAT · 2 marks
In the given circuit, the maximum power (in Watts) that can be transferred to the load RLR_L is ________.
Official PYQ2015Electronic DevicesNAT · 2 marks
The built-in potential of an abrupt p-n junction is 0.750.75 V. If its junction capacitance (CJ)(C_J) at a reverse bias (VR)(V_R) of 1.25 V1.25 \: V is 55 pF, the value of CJC_J (in pF) when VR=7.25 VV_R = 7.25 \: V is ________.
Official PYQ2015Analog CircuitsBJT and MOSFET AmplifiersNAT · 2 marks
A MOSFET in saturation has a drain current of 11 mA for VDS=0.5 VV_{DS} =0.5 \: V. If the channel length modulation coefficient is 0.05 V−10.05 \: V^{-1}, the output resistance (in kΩk \Omega) of the MOSFET is ___________.
Official PYQ2015Electronic DevicesNAT · 2 marks
For a silicon diode with long P and N regions, the accepter and donor impurity concentrations are 1×1017 cm−31 \times 10^{17} \:cm^{-3} and 1×1015 cm−31 \times 10^{15} \: cm^{-3}, respectively. The lifetimes of electrons in P region and holes in N region are both 100 μs100 \: \mu s. The electron and hole diffusion coefficients are 49 cm2/s49 \: cm^2/s and 36 cm2/s36 \: cm^2/s, …
Official PYQ2015Digital CircuitsCombinatorial CircuitsMCQ · 2 marks
The Boolean expression F(X,Y,Z)=X‾ Y Z‾+X Y‾ Z‾+X Y Z‾+X Y ZF(X,Y,Z) = \overline{X} \: Y \: \overline{Z}+ X \: \overline{Y} \: \overline{Z}+ X \: Y \: \overline{Z} + X \: Y \: Z converted into the canonical product of sum (POS) form is
Official PYQ2015ElectromagneticsPlane Waves and PropertiesNAT · 2 marks
All the logic gates shown in the figure have a propagation delay of 2020 ns. Let A=C=0A=C=0 and B=1B=1 until time t=0t=0. At t=0t=0, all the inputs flip (i.e., A=C=1A=C=1 and B=0B=0) and remain in that state. For t>0t>0, output Z=1Z=1 for a duration (in ns) of ________.
Official PYQ2015Digital CircuitsCombinatorial CircuitsMCQ · 2 marks
A 33-input majority gate is defined by the logic function M(a,b,c)=ab+bc+caM(a,b,c)=ab+bc+ca. Which one of the following gates is represented by the function M(M(a,b,c)‾,M(a,b,c‾),c)M(\overline{M(a,b,c)}, M(a,b,\overline{c}),c)?
Official PYQ2015Analog CircuitsBJT and MOSFET AmplifiersMCQ · 2 marks
For the NMOSFET in the circuit shown, the threshold voltage is VthV_{th}, where Vth>0V_{th}>0. The source voltage VSSV_{SS} is varied from 00 to VDDV_{DD}. Neglecting the channel length modulation, the drain current IDI_D as a function of VSSV_{SS} is represented by
Official PYQ2015Analog CircuitsOp-amp CircuitsNAT · 2 marks
In the circuit shown, assume that the opamp is ideal. The bridge output voltage V0V_0 (in mV) for δ=0.05\delta=0.05 is __________