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 PYQ2004Digital CircuitsCombinatorial CircuitsMCQ · 1 mark
The Boolean expression AC + BC‾\text{AC + B} \overline{\text{C}} is equivalent to
Official PYQ2004Digital CircuitsNumber RepresentationsMCQ · 1 mark
11001,100111001, 1001 and 111001111001 correspond to the 22's complement representation of which one of the following sets of number ?
Official PYQ2004Digital CircuitsComputer OrganizationMCQ · 1 mark
The 82558255 Programmable Peripheral Interface is used as described below. An A/D converter is interfaced to a microprocessor through 8255.8255. The conversion is initiated by a signal from the 82558255 on Port C. A signal on Port C causes data to be strobed into Port A. Two computers exchange data using a pair of 8255s8255 \mathrm{s}. Port A works as a …
Official PYQ2004Digital CircuitsComputer OrganizationMCQ · 1 mark
The number of memory cycles required to execute the following 80858085 instructions LDA 3000 H\text{LDA 3000 H} LXI D, FOF 1 H\text{LXI D, FOF 1 H} would be
Official PYQ2004Digital CircuitsSequential CircuitsMCQ · 1 mark
In the modulo-66 ripple counter shown in the given figure, the output of the 22-input gate is used to clear the J-K flip-flops. The 22-input gate is
Official PYQ2004Digital CircuitsComputer OrganizationMCQ · 1 mark
Consider the sequence of 80858085 instructions given below. LXI H, 9258, MOV A, M, CMA, MOV M, A\text{LXI H, 9258, MOV A, M, CMA, MOV M, A} Which one of the following is performed by this sequence?
Official PYQ2004Digital CircuitsCombinatorial CircuitsMCQ · 1 mark
A Boolean function ff of two variables xx and yy is defined as follows: f(0,0)=f(0,1)=f(1,1)=1;f(1,0)=0f(0,0)=f(0,1)=f(1,1)=1 ; \quad f(1,0)=0 Assuming complements of xx and yy are not available, a minimum cost solution for realizing ff using only 22-input NOR gates and 22-input OR gates (each having unit cost) would have a total cost of
Official PYQ2004Digital CircuitsComputer OrganizationMCQ · 1 mark
It is desired to multiply the numbers 0AH0 \mathrm{AH} by 0BH0 \mathrm{BH} and store the result in the accumulator. The numbers are available in registers BB and CC respectively. A Part of the 80858085 program for this purpose is given below: MV1 A, 00H\qquad \qquad \text{MV1 A, 00H} Loop;…....……….….\text{Loop;}…....……….…. .…...…….....….\qquad.…...…….....…. …
Official PYQ2004Networks, Signals and SystemsContinuous-time SignalsMCQ · 1 mark
A 1  kHz1 \; \mathrm{kHz} sinusoidal signal is ideally sampled at 15001500 samples/sec and the sampled signal is passed through an ideal low-pass filter with cut-off frequencey 800 Hz800 \mathrm{~Hz}. The output signal has the frequency
Official PYQ2004Networks, Signals and SystemsLTI SystemsMCQ · 1 mark
A rectangular pulse train s(t)s(t) as shown in the figure is convolved with the signal cos⁡2(4p×103t)\cos ^{2}\left(4 p \times 10^{3} t\right). The convolved signal will be a
Official PYQ2004Networks, Signals and SystemsLTI SystemsMCQ · 1 mark
A causal LTI\text{LTI} system is described by the difference equation 2y[n]=αy[n−2]−2x[n]+βx[n−1]2 y[n]=\alpha y[n-2]-2 x[n]+\beta x[n-1] The system is stable only if
Official PYQ2004Control SystemsMCQ · 1 mark
A causal system having the transfer function H(s)=1s+2\mathrm{H}(s)=\frac{1}{s+2} is excited with 10u(t)10 u(t). The time at which the output reaches 99%99 \% of its steady state value is
Official PYQ2004Networks, Signals and SystemsLTI SystemsMCQ · 1 mark
The impulse response h∣n∣h|n| of a linear time invariant system is given as h[n]={−22n=1,−142n=2,−20, otherwise h[n]=\left\{\begin{array}{cc} -2 \sqrt{2} & n=1,-1 \\ 4 \sqrt{2} & n=2,-2 \\ 0, & \text{ otherwise } \end{array}\right. If the input to the above system is the sequence ejπn/4\mathrm{e}^{j \pi n / 4}, then the output is
Official PYQ2004Networks, Signals and SystemsContinuous-time SignalsMCQ · 1 mark
Let x(t)x(t) and y(t)y(t) (with Fourier transforms X(f)X(f) and Y(f)Y(f) respectively) be related as shown in the given figure. Then Y(f)Y(f) is
Official PYQ2004Control SystemsMCQ · 1 mark
A system has poles at 0.01 Hz,1 Hz0.01 \mathrm{~Hz}, 1 \mathrm{~Hz} and 80 Hz80 \mathrm{~Hz}; zeros at 5 Hz,100 Hz5 \mathrm{~Hz}, 100 \mathrm{~Hz} and 200 Hz200 \mathrm{~Hz}. The approximate phase of the system response at 20 Hz20 \mathrm{~Hz} is
Official PYQ2004Control SystemsMCQ · 1 mark
Consider the signal flow graph shown in the figure below. The gain x5x1\frac{x_{5}}{x_{1}} is
Official PYQ2004Engineering MathematicsLinear AlgebraMCQ · 1 mark
If A=[−221−3]A=\left[\begin{array}{cc}-2 & 2 \\ 1 & -3\end{array}\right], then sin⁡At\sin A t is
Official PYQ2004Control SystemsMCQ · 1 mark
The open-loop transfer function of a unity feedback system is G(s)=Ks(s2+s+2)(s+3)G(s)=\frac{K}{s\left(s^{2}+s+2\right)(s+3)} The range of K\mathrm{K} for which the system is stable is
Official PYQ2004Control SystemsMCQ · 1 mark
For the polynomial P(s)=s5+s4+2s3+2s2+3s+15P(s)=s^{5}+s^{4}+2 s^{3}+2 s^{2}+3 s+15, the number of roots which lie in the right half of the s-plane is
Official PYQ2004Control SystemsMCQ · 1 mark
The state variable equations of a system are: 1.  x1=−3x1−x2+u2.  x2=2x1y=x1+u\begin{array}{l} 1. \; x_{1}=-3 x_{1}-x_{2}+u \\ 2. \; x_{2}=2 x_{1} \\ \quad y=x_{1}+u \end{array} The system is