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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 PYQ2017Engineering MathematicsCalculusMCQ · 2 marks
Let f(x)=ex+x2f(x)=e^{x+x^{2}} for real xx . From among the following, choose the Taylor series approximation of f(x)f(x) around x=0x=0, which includes all powers of xx less than or equal to 33.
Official PYQ2017Engineering MathematicsCalculusNAT · 2 marks
A three dimensional region RR of finite volume is described by x2+y2≤z3;  0≤z≤1,x^2 + y^2 \leq z^3; \: \: 0 \leq z \leq 1, where x,y,zx,y,z are real. The volume of RR (up to two decimal places) is _________
Official PYQ2017Engineering MathematicsCalculusNAT · 2 marks
Let I=∫c(2zdx+2ydy+2xdx)I=\int_{c}\left ( 2zdx+2ydy+2xdx \right ) where x,y,zx,y,z are real, and let CC be the straight line segment from point A:(0,2,1)A:(0,2,1) to point B:(4,1,−1)B:(4,1,-1).The value of II is ____________.
Official PYQ2017Engineering MathematicsDifferential EquationsMCQ · 2 marks
Which one of the following is the general solution of the first order differential equation dydx=(x+y−1)2,\frac{dy}{dx}=(x+y-1)^{2}, where x,yx,y are real?
Official PYQ2017Engineering MathematicsCalculusNAT · 2 marks
Starting with x=1x=1, the solution of the equation x3+x=1x^{3}+x=1, after two iterations of Newton-Raphson’s method (up to two decimal places) is__________.
Official PYQ2017Networks, Signals and SystemsContinuous-time SignalsMCQ · 2 marks
Let x(t)x(t) be a continuous time periodic signal with fundamental period T=1T=1 seconds.Let ak{a_{k} } be the complex Fourier series coefficients of x(t)x(t), where kk is integer valued. Consider the following statements about x(3t)x(3t): The complex Fourier series coefficients of x(3t)x(3t) are ak{a_{k}} where kk is integer valued The complex …
Official PYQ2017Networks, Signals and SystemsLTI SystemsNAT · 2 marks
Two discrete-time signals x[n]x[n] and h[n]h[n] are both non-zero only for n=0,1,2n=0,1,2, and are zero otherwise .It is given that x[0]=1, x[1]=2, x[2]=1, h[0]=1x[0]=1, \: x[1]=2, \: x[2]=1, \: h[0]=1 Let y[n]y[n] be the linear convolution of x[n]x[n] and h[n]h[n]. Given that y[1]=3y[1]=3 and y[2]=4y[2]=4, the value of the expression (10y[3]+y[4])(10y[3]+y[4]) is__________.
Official PYQ2017Networks, Signals and SystemsDiscrete-time SignalsNAT · 2 marks
Let h[n]h[n] be the impulse response of a discrete-time linear time invariant(LTI) filter. The impulse response is given by h[0]=13; h[1]=13; h[2]=13; and h[n]=0 for n<0 and n>2.h[0]=\frac{1}{3}; \, h[1]=\frac{1}{3}; \, h[2]=\frac{1}{3} \text{; and } h[n]=0 \text{ for } n<0 \text{ and } n>2. Let H(ω)H(\omega) be the discrete-time Fourier transform (DTFT) of h[n]h[n], where ω\omega is the normalized …
Official PYQ2017Networks, Signals and SystemsCircuit AnalysisNAT · 2 marks
The figure shows an RLC circuit excited by the sinusoidal voltage 100cos⁡(3t)100 \cos(3t) Volts, where tt is in seconds. The ratio amplitude of V2amplitude of V1\frac{\text{amplitude of }V_{2}}{\text{amplitude of }V{1}} is______.
Official PYQ2017Analog CircuitsBJT and MOSFET AmplifiersNAT · 2 marks
In the circuit shown, the voltage VIN(t)V_{IN}(t) is described by: VIN(t)={0,for t<015Voltsfor t≥0V_{IN}(t)=\begin{cases} 0, & \text{for } t< 0 \\ 15 \text{Volts} & \text{for } t\geq 0 \end{cases} where tt is in seconds. The time (in seconds) at which the current II in the circuit will reach the value 22 Amperes is ___________.
Official PYQ2017Electronic DevicesNAT · 2 marks
The dependence of drift velocity of electrons on electric field in a semiconductor is shown below. The semiconductor has a uniform electron concentration of n=1×1016cm3n=1 \times 10^{16} cm^{3} and electronic charge q=1.6×10−19Cq=1.6 \times 10 ^{-19}C. If a bias of 5V5 V is applied across a 1µm1 µm region of this semiconductor, the resulting current density in this …
Official PYQ2017Electronic DevicesNAT · 2 marks
As shown , a uniformly doped Silicon bar of length L=0.1μmL=0.1\mu m with a donor concentration ND=1016cm−3N_{D}=10^{16}cm^{-3} is illuminated at x=0x=0 such that electron and hole pairs are generated at the rate of GL=GL0(1−xL),0≤x≤LG_{L}=G_{L0}(1-\frac{x}{L}), 0\leq x\leq L, where GL0=1017cm−3s−1G_{L0}=10^{17}cm^{-3}s^{-1} . Hole life time is 10−4s10^{-4} s, electronic charge …
Official PYQ2017Electronic DevicesNAT · 2 marks
As shown, two Silicon (Si) abrupt p−np-n junction diodes are fabricated with uniform donor doping concentrations of ND1=1014cm−3N_{D1}=10^{14} cm^{-3} and ND2=1016cm−3N_{D2}=10^{16}cm^{-3} in the nn-regions of the diodes, and uniform acceptor doping concentrations of NA1=1014cm−3N_{A1}=10^{14} cm^{-3} and NA2=1016cm−3N_{A2}=10^{16} cm{-3} in the pp-regions of the …
Official PYQ2017Analog CircuitsBJT and MOSFET AmplifiersNAT · 2 marks
In the figure shown, the npnnpn transistor acts as a switch. For the input Vin(t)V_{in}(t) as shown in the figure, the transistor switches between the cut-off and saturation regions of operation, when TT is large. Assume collector-to-emitter voltage at saturation VCE(sat)=0.2VV_{CE(sat)}=0.2V and base-to-emitter voltage VBE=0.7VV_{BE}=0.7V.The minimum value of the …
Official PYQ2017Analog CircuitsBJT and MOSFET AmplifiersNAT · 2 marks
For the circuit shown, assume that the NMOS transistor is in saturation. Its threshold voltage Vtn=1VV_{tn}=1V and its transconductance parameter μnCox(WL)=1 mA/V2\mu_{n}C_{ox}\big(\frac{W}{L}\big)=1 \: mA/V^{2}.Neglect channel length modulation and body bias effects. Under these conditions, the drain current IDI_{D} in mAmA is ________.
Official PYQ2017Analog CircuitsBJT and MOSFET AmplifiersNAT · 2 marks
For the DC analysis of the Common-Emitter amplifier shown, neglect the base current and assume that the emitter and collector currents are equal. Given that VT=25mV,VBE=0.7VV_{T}=25mV,V_{BE}=0.7V, and the BJT output resistance ror_{o} is practically infinite. Under these conditions, the midband voltage gain magnitude, Av=∣vo/vi∣A_{v}=\mid v_{o}/v_{i} \mid, V/V is …
Official PYQ2017Analog CircuitsOp-amp CircuitsNAT · 2 marks
The amplifier circuit shown in the figure is implemented using a compensated operational amplifier (op-amp), and has an open-loop voltage gain, A0=105V/VA_{0}=10^{5}V/V and an open-loop cut-off frequency, fc=8Hzf_{c}=8Hz. The voltage gain of the amplifier at 1515 kHz, in V/V, is____________.
Official PYQ2017Digital CircuitsCombinatorial CircuitsMCQ · 2 marks
Which one of the following gives the simplified sum of products expression for the Boolean function F=m0+m2+m3+m5F=m_{0}+m_{2}+m_{3}+m_{5}, where m0,m2,m3m_{0},m_{2},m_{3} and m5m_{5} are minterms corresponding to the inputs A,BA,B and CC with AA as the MSBMSB and CC as the LSBLSB?
Official PYQ2017Digital CircuitsSequential CircuitsNAT · 2 marks
A 44-bit shift register circuit configured for right-shift operation, i.e. Din→A,A→B,B→C,C→DD_{in}\rightarrow A,A\rightarrow B,B\rightarrow C,C\rightarrow D, is shown. If the present state of the shift register is ABCD=1101ABCD=1101, the number of clock cycles required to reach the state ABCD=1111ABCD=1111 is _________.
Official PYQ2017Digital CircuitsComputer OrganizationMCQ · 2 marks
The following FIVE instructions were executed on an 80858085 microprocessor. MVI A, 3333H MVI B, 7878H ADD B CMA ANI 3232H The Accumulator value immediately after the execution of the fifth instruction is