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GATE 2014 Electronics & Communication

142 questions across 4 sessions

Set 1

PYQ 1

For a parallel plate transmission line, let v be the speed of propagation and Z be the characteristic impedance. Neglecting fringe effects, a redution of the spacing between the pl...

Electromagnetics·MCQ·easy·✓ keyed
PYQ 2

A good current buffer has

Analog Circuits·MCQ·✓ keyed
PYQ 3

Consider the Boolean function, F(w,z,y,z)=wy+ xy +$$\overline w \,xyz + \overline w \,\overline x y\, + xz + \,\overline {x\,} \,\overline y \,$$ $$\overline z $$ Which one of the...

Digital Circuits·MCQ·medium·✓ keyed
PYQ 4

A Y-network has resistances of 10Ω each in two of its arms, while the third arm has a resistance of 11Ω in the equivalent ∆ − network, the lowest value (in Ω) among the three resis...

Network Theory·NAT·easy
PYQ 5

For maximum power transfer between two cascaded sections of an electrical network, the relationship between the output impedance Z 1 of the first section to the input impedance Z 2...

Network Theory·MCQ·easy·✓ keyed
PYQ 6

A 230 V rms source supplies power to two loads connected in parallel. The first load draws 10 kW at 0.8 leading power factor and the second one draws 10 kVA at 0.8 lagging power fa...

Network Theory·MCQ·medium·✓ keyed
PYQ 7

The forward path transfer function of a unity negative feedback system is given by $$$G\left(s\right)\;=\;\frac k{\left(s\;+\;2\right)\left(s\;-\;1\right)}$$$ The value of K which...

Control Systems·NAT·easy
PYQ 8

Let $$X$$ be a real - valued random variable with $$E\left[ X \right]$$ and $$E\left[ {{X^2}} \right]$$ denoting the mean values of $$X$$ and $${{X^2}}$$, respectively. The relatio...

Engineering Mathematics·MCQ·easy·✓ keyed
PYQ 9

Find the odd one from the following group: W,E,K,O I,Q,W,A F,N,T,X N,V,B,D

General Aptitude·MCQ·easy·✓ keyed
PYQ 10

$$C$$ is a closed path in the $$z-$$plane given by $$\left| z \right| = 3.$$ The value of the integral $$\oint\limits_c {{{{z^2} - z + 4j} \over {z + 2j}}dz} $$ is

Engineering Mathematics·MCQ·medium·✓ keyed
PYQ 11

The Boolean expression (X+Y)(X+$$\overline Y $$)+($$\overline {(X\overline Y ) + \overline X } $$ simplifies to

Digital Circuits·MCQ·easy·✓ keyed
PYQ 12

For submitting tax returns, all resident males with annual income below Rs 10 lakh should fill up Form P and all resident females with income below Rs 8 lakh should fill up Form Al...

General Aptitude·MCQ·easy·✓ keyed
PYQ 13

The volume under the surface $$z\left( {x,y} \right) = x + y$$ and above the triangle in the $$xy$$ plane defined by $$\left\{ {0 \le y \le x} \right.$$ and $$\,\left. {0 \le x \le...

Engineering Mathematics·NAT·easy
PYQ 14

The Taylor series expansion of $$3$$ $$sin$$ $$x$$ $$+2cos$$ $$x$$ is

Engineering Mathematics·MCQ·easy·✓ keyed
PYQ 15

A BJT is baised in forward active mode Assume V BE = 0.7 V, kT/q = 25 mV and reverse saturation current I s = 10 -13 A. The transconductance of the BJT (in mA/V) is

Analog Circuits·NAT·medium
PYQ 16

A system is described by the following differential equation, where $$u(t)$$ is the input to the system and $$y(t)$$ is the output of the system. $$$\mathop y\limits^ \bullet \left...

Engineering Mathematics·MCQ·easy·✓ keyed
PYQ 17

In a housing society, half of the families have a single child per family, while the remaining half have two children per family. The probability that a child picked at random, has...

Engineering Mathematics·NAT·easy
PYQ 18

Consider a random process $$X\left( t \right) = \sqrt 2 \sin \left( {2\pi t + \varphi } \right),$$ where the random phase $$\varphi $$ is uniformly distributed in the interval $$\l...

Communications·MCQ·easy·✓ keyed
PYQ 19

The capacity of a Binary Symmetric Channel (BSC) with cross - over probability 0.5 is ______ .

Communications·NAT·easy
PYQ 20

In a code - division multiple access (CDMA) system with N = 8 chips, the maximum number of users who can be assigned mutually orthogonal signature sequences is _______.

Communications·NAT·easy
PYQ 21

A two - port network has scattering parameters given by $$[S]$$ $$ = \left[ {\matrix{ {{s_{11}}} & {{s_{12}}} \cr {{s_{21}}} & {{s_{22}}} \cr } } \right].$$ If the port - 2 of the...

Electromagnetics·MCQ·medium·✓ keyed
PYQ 22

A fair coin is tossed repeatedly until a 'Head' appears for the first time. Let L be the number of tosses to get this first 'Head'. The entropy H (L) in bits is _______________.

Communications·NAT·medium
PYQ 23

In spherical coordinates, let $${{{\widehat a}_{_0}},\,{{\widehat a}_{_\phi }}}$$ denote unit vectors along the $$\theta ,\,\,\phi $$directions. $$$E = {{100} \over r}\sin \,\theta...

Electromagnetics·NAT·medium
PYQ 24

$$A$$ real $$\left( {4\,\, \times \,\,4} \right)$$ matrix $$A$$ satisfies the equation $${A^2} = {\rm I},$$ where $${\rm I}$$ is the $$\left( {4\,\, \times \,\,4} \right)$$ identit...

Engineering Mathematics·NAT·easy
PYQ 25

Let $$\,{X_1},\,\,{X_2}\,\,$$ and $$\,{X_3}\,$$ be independent and identically distributed random variables with the uniform distribution on $$\left[ {0,1} \right].$$ The probabili...

Engineering Mathematics·NAT·easy
PYQ 26

For matrices of same dimension $$M,N$$ and scalar $$c,$$ which one of these properties DOES NOT ALWAYS hold ?

Engineering Mathematics·MCQ·easy·✓ keyed
PYQ 27

The phase margin in degrees of G(s)=$${{10} \over {\left( {s + 0.1} \right)\left( {s + 1} \right)\left( {s + 10} \right)}},$$ using the asymptotic Bode plot is ______

Control Systems·NAT·medium
PYQ 28

You are given three coins: one has heads on both faces, the second has tails on both faces, and the third has a head on one face and a tail on the other. You choose a coin at rando...

General Aptitude·MCQ·medium·✓ keyed
PYQ 29

Consider the matrix $${J_6} = \left[ {\matrix{ 0 & 0 & 0 & 0 & 0 & 1 \cr 0 & 0 & 0 & 0 & 1 & 0 \cr 0 & 0 & 0 & 1 & 0 & 0 \cr 0 & 0 & 1 & 0 & 0 & 0 \cr 0 & 1 & 0 & 0 & 0 & 0 \cr 1 &...

Engineering Mathematics·NAT·medium
PYQ 30

A train that is 280 meters long, traveling at a uniform speed, crosses a platform in 60 seconds and passes a man standing on the platform in 20 seconds. What is the length of the p...

General Aptitude·NAT·easy
PYQ 31

Consider a discrete time periodic signal x$$\left[ n \right]$$= $$\sin \left( {{{\pi n} \over 5}} \right)$$. Let a k be the complex Fourier serier coefficients of x$$\left[ n \righ...

Signals and Systems·NAT·easy
PYQ 32

When the optical power incident on a photodiode is 10μW and the responsivity is 0.8 A/W, the photocurrent generated (in μA) is ________.

Electronic Devices and Vlsi·NAT·easy
PYQ 33

If fixed positive charges are present in the gate oxide of an n-channel enhancement type MOSFET, it will lead to

Electronic Devices and Vlsi·MCQ·easy·✓ keyed
PYQ 34

A continuous, linear time - invariant fiilter has an impulse response h(t) described by $$h\left( t \right) = \left\{ {\matrix{ {3\,for\,0 \le t \le 3} \cr {0\,otherwise} \cr } } \...

Signals and Systems·NAT·easy
PYQ 35

For a function g(t), it is given that $$\int_{ - \infty }^\infty {g(t){e^{ - j\omega t}}dt = \omega {e^{ - 2{\omega ^2}}}} $$ for any real value $$\omega $$. If y(t)=$$\int_{ - \in...

Signals and Systems·MCQ·medium·✓ keyed
PYQ 36

A system is described by the following differential equation, where u(t) is the input to the system and y(t) is output of the system $$\mathop y\limits^ \bullet \left( t \right) +...

Signals and Systems·MCQ·easy·✓ keyed
PYQ 37

Let x $$\left[ n\right]$$= $${\left( { - {1 \over 9}} \right)^n}\,u(n) - {\left( { - {1 \over 3}} \right)^n}u( - n - 1).$$ The region of Convergence (ROC) of the z-tansform of x$$\...

Signals and Systems·MCQ·easy·✓ keyed
PYQ 38

Consider two real valued signals, $$x\left( t \right)$$ band - limited to $$\,\left[ { - 500Hz,\,\,500Hz} \right]$$ and $$y\left( t \right)$$ band - limited to $$\,\left[ { - 1\,\,...

Signals and Systems·NAT·easy
PYQ 39

A depletion type N -channel MOSFET is biased in its linear region for use as a voltage controlled resistor. Assume threshold voltage V TH = -0.5 V, V GS = 2.0 V, V DS = 5 V, W/L=10...

Electronic Devices and Vlsi·NAT·medium
PYQ 40

A discrete - time signal x[n] = $${\rm{sin(}}\,{\pi ^2}n)$$, n being an integer is

Signals and Systems·MCQ·easy·✓ keyed

Set 2

PYQ 1

Which one of the following field patterns represents a TEM wave traveling in the positive $$x$$ direction?

Electromagnetics·MCQ·✓ keyed
PYQ 2

Norton's theorem states that a complex network connected to a load can be replaced with an equivalent impedance

Network Theory·MCQ·✓ keyed
PYQ 3

A series LCR circuit is operated at a frequency different from its resonant frequency. The operating frequency is such that the current leads the supply voltage. The magnitude of c...

Network Theory·NAT·medium
PYQ 4

The natural frequency of an undamped second-order system is 40 rad/s. If the system is damped with a damping ratio 0.3, the damped natural frequency in rad/s is ________.

Control Systems·NAT·easy
PYQ 5

The number of bytes required to represent the decimal number 1856357 in packed BCD (Binary Coded Decimal) form is __________ .

Digital Circuits·NAT·easy
PYQ 6

The system of linear equations $$\left( {\matrix{ 2 & 1 & 3 \cr 3 & 0 & 1 \cr 1 & 2 & 5 \cr } } \right)\left( {\matrix{ a \cr b \cr c \cr } } \right) = \left( {\matrix{ 5 \cr { - 4...

Engineering Mathematics·MCQ·easy·✓ keyed
PYQ 7

Let $$X$$ be a random variable which is uniformly chosen from the set of positive odd numbers less than $$100.$$ The expectation, $$E\left[ X \right],$$ is __________.

Engineering Mathematics·NAT·easy
PYQ 8

For an n - variable Boolean function maximum number of prime implicants is

Digital Circuits·MCQ·medium·✓ keyed
PYQ 9

The determinant of matrix $$A$$ is $$5$$ and the determinant of matrix $$B$$ is $$40.$$ The determinant of matrix $$AB$$ is _______.

Engineering Mathematics·NAT·easy
PYQ 10

For $$0 \le t < \infty ,$$ the maximum value of the function $$f\left( t \right) = {e^{ - t}} - 2{e^{ - 2t}}\,$$ occurs at

Engineering Mathematics·MCQ·easy·✓ keyed
PYQ 11

An unforced linear time invariant (LTI) system is represented by $$$\left[ {\matrix{ {\mathop {{x_1}}\limits^ \bullet } \cr {\mathop {{x_2}}\limits^ \bullet } \cr } } \right] = \le...

Control Systems·MCQ·easy·✓ keyed
PYQ 12

If $$\,\overrightarrow r = x\widehat a{}_x + y\widehat a{}_y + z\widehat a{}_z\,\,\,\,$$ and $$\,\left| {\overrightarrow r } \right| = r,$$ then div $$\left( {{r^2}\nabla \left( {\...

Engineering Mathematics·NAT·medium
PYQ 13

In a half-subtractor circuit with X and Y as inputs, the Borrow (M) and Difference (N = X - Y) are given by

Digital Circuits·MCQ·easy·✓ keyed
PYQ 14

The capacity of band-limited additive white Gaussian noise (AWGN) channel is given by $$C = \,W\,\,{\log _2}\left( {1 + {P \over {{\sigma ^2}\,W}}} \right)$$ bits per second (bps),...

Communications·MCQ·medium·✓ keyed
PYQ 15

The input to a 1-bit quantizer is a random variable X with pdf $${f_x}(x) = 2{e^{ - 2x}}\,\,for\,\,x \ge 0$$ and $${f_x}(x) = 0\,\,for\,\,x\, < \,0$$. For outputs to be of equal pr...

Communications·NAT·medium
PYQ 16

The power spectral density of a real stationary random process X(t) is given by $$${S_x}\left( f \right) = \left\{ {\matrix{ {{1 \over W},\left| f \right| \le W} \cr {0,\left| f \r...

Communications·NAT·medium
PYQ 17

For a rectangular waveguide of internal dimensions $$a\,\, \times \,\,b$$ (a > b), the cut-off frequency for the $$T{E_{11}}$$ mode is the arithmetic mean of the cut-off frequencie...

Electromagnetics·NAT·medium
PYQ 18

Coherent orthogonal binary FSK modulation is used to transmit two equiprobable symbol waveforms $${s_1}\,(t)\, = \,\alpha \,\,\cos \,\,\,2\,\pi {f_1}\,t\,and\,\,{s_{2\,}}(t)\,\, =...

Communications·MCQ·medium·✓ keyed
PYQ 19

If the characteristic equation of the differential equation $$\,{{{d^2}y} \over {d{x^2}}} + 2\alpha {{dy} \over {dx}} + y = 0\,\,$$ has two equal roots, then the values of $$\alpha...

Engineering Mathematics·MCQ·easy·✓ keyed
PYQ 20

The real part of an analytic function $$f(z)$$ where $$z=x+jy$$ is given by $${e^{ - y}}\cos \left( x \right).$$ The imaginary part of $$f(z)$$ is

Engineering Mathematics·MCQ·easy·✓ keyed
PYQ 21

The maximum value of the determinant among all $$2 \times 2$$ real symmetric matrices with trace $$14$$ is ______.

Engineering Mathematics·NAT·easy
PYQ 22

The value of $$\mathop {\lim }\limits_{x \to \infty } {\left( {1 + {1 \over x}} \right)^x}\,\,$$ is

Engineering Mathematics·MCQ·easy·✓ keyed
PYQ 23

The value of the integral $$\int\limits_{ - \infty }^\infty {\sin \,{c^2}} $$ (5t) dt is

Signals and Systems·NAT·medium
PYQ 24

Assume electronic charge q = 1.6×10 -19 C, kT/q = 25 mV and electron mobility μ n = 1000 cm 2 /V-s. If the concentration gradient of electrons injected into a P-type silicon sample...

Electronic Devices and Vlsi·NAT·easy
PYQ 25

An increase in the base recombination of a BJT will increase

Electronic Devices and Vlsi·MCQ·medium·✓ keyed
PYQ 26

In CMOS technology, shallow P-well or N-well regions can be formed using

Electronic Devices and Vlsi·MCQ·easy·✓ keyed
PYQ 27

The input-output relationship of a causal stable LTI system is given as 𝑦[𝑛] = 𝛼 𝑦[𝑛 − 1] + $$\beta $$ x[n]. If the impulse response h[n] of this system satisfies the conditio...

Signals and Systems·MCQ·easy·✓ keyed
PYQ 28

Consider a discrete-time signal $$x\left[ n \right] = \left\{ {\matrix{ {n\,\,for\,\,0 \le n \le 10} \cr {0\,\,otherwise} \cr } } \right.$$ If $$y\left[ n \right]$$ is the convolut...

Signals and Systems·NAT·easy
PYQ 29

Let x$$\left[ n \right]$$ = x$$\left[- n \right]$$ . Let X(z) be the z-transform of x$$\left[ n \right]$$. if 0.5 +j 0.25 is a zero of X(z), which one of the folowing must also be...

Signals and Systems·MCQ·easy·✓ keyed
PYQ 30

An FIR system is described by the system function $$$H(z) = 1 + {7 \over 2}{z^{ - 1}} + {3 \over 2}{z^{ - 2}}$$$

Signals and Systems·MCQ·medium·✓ keyed
PYQ 31

If the electric field of a plane wave is $$$\overrightarrow E \left( {z,t} \right) = \widehat x3\cos \left( {\omega t - kz + {{30}^ \circ }} \right) - \widehat y4\sin \left( {\omeg...

Electromagnetics·MCQ·medium·✓ keyed

Set 3

PYQ 1

If $$z=xy$$ $$ln(xy),$$ then

Engineering Mathematics·MCQ·✓ keyed
PYQ 2

A series RC circuit is connected to a DC voltage source at time t = 0. The relation between the source voltage V S , the resistance R, the capacitance C, and the current i(t) is gi...

Network Theory·MCQ·✓ keyed
PYQ 3

The input $$-3\mathrm e^{2\mathrm t}\;\mathrm u\left(\mathrm t\right)$$, where u(t) is the unit step function, is applied to a system with transfer function $$\frac{s-2}{s+3}$$. If...

Control Systems·NAT·medium
PYQ 4

If X and Y are inputs and the Difference (D = X – Y) and the Borrow (B) are the outputs, which one of the following diagrams implements a half-subtractor?

Digital Circuits·MCQ·easy·✓ keyed
PYQ 5

The maximum value of the function $$\,f\left( x \right) = \ln \left( {1 + x} \right) - x$$ (where $$x > - 1$$ ) occurs at $$x=$$________.

Engineering Mathematics·NAT·easy
PYQ 6

The maximum value of $$f\left( x \right) = 2{x^3} - 9{x^2} + 12x - 3$$ in the interval $$\,0 \le x \le 3$$ is __________.

Engineering Mathematics·NAT·easy
PYQ 7

If WL is the Word Line and BL the Bit Line, an SRAM cell is shown in

Digital Circuits·MCQ·easy·✓ keyed
PYQ 8

Which ONE of the following is a linear non - homogeneous differential equation , where $$x$$ and $$y$$ are the independent and dependent variables respectively?

Engineering Mathematics·MCQ·easy·✓ keyed
PYQ 9

The desirable characteristics of a transconductance amplifier are

Analog Circuits·MCQ·easy·✓ keyed
PYQ 10

Let $$X(t)$$ be a wide sense stationary $$(WSS)$$ random procfess with power spectral density $${S_x}\left( f \right)$$. If $$Y(t)$$ is the process defined as $$Y(t) = X(2t - 1)$$,...

Communications·MCQ·medium·✓ keyed
PYQ 11

Consider an air filled rectangular waveguide with a cross-section of $$5\,\,cm\,\, \times \,\,3\,cm$$. For this waveguide, the cut-off frequency (in MHz) of $$T{E_{21}}\,$$ mode is...

Electromagnetics·NAT·easy
PYQ 12

Assume that a plane wave in air with an electric field $$\overrightarrow E = 10\cos \left( {\omega t - 3x - \sqrt {3z} } \right){\widehat a_{_y}}\,\,\,V/m$$ is incident on a non-ma...

Electromagnetics·NAT·medium
PYQ 13

In a PCA system, the signal $$m(t) = \{ \sin (100\,\pi \,t)\, + \cos (100\,\pi \,t\} $$ V is sampled at the Nyquist rate. The samples are processed by a uniform quantizer with step...

Communications·NAT·medium
PYQ 14

A real band-limited random process $$X( t )$$ has two -sided power spectral density $$${S_x}\left( f \right) = \left\{ {\matrix{ {{{10}^{ - 6}}\left( {3000 - \left| f \right|} \rig...

Communications·NAT·medium
PYQ 15

Let $${X_1},\,{X_2},$$ and $${X_3}$$ be independent and identically distributed random variables with the uniform distribution on $$\left[ {0,\,1} \right]$$. The probability $$P\le...

Communications·NAT·medium
PYQ 16

A fair coin is tossed repeatedly till both head and tail appear at least once. The average number of tosses required is ________.

Engineering Mathematics·NAT·medium
PYQ 17

Match the application to appropriate numerical method Applications $$P1:$$ Numerical integration $$P2:$$ Solution to a transcendental equation $$P3:$$ Solution to a system of linea...

Engineering Mathematics·MTF·easy·✓ keyed
PYQ 18

Let $${X_1},{X_{2,}}$$ and $${X_{3,}}$$ be independent and identically distributed random variables with the uniform distribution on $$\left[ {0,1} \right].$$ The probability $$P\l...

Engineering Mathematics·NAT·medium
PYQ 19

Which one of the following statements is NOT true for a square matrix $$A$$?

Engineering Mathematics·MCQ·easy·✓ keyed
PYQ 20

The state equation of a second-order linear system is given by $$\mathop x\limits^ \bullet \left( t \right) = Ax\left( t \right),x\left( 0 \right) = {x_0}.$$ For $${x_0} = \left[ {...

Control Systems·MCQ·medium·✓ keyed
PYQ 21

An unbiased coin is tossed an infinite number of times. The probability that the fourth head appears at the tenth toss is

Engineering Mathematics·MCQ·medium·✓ keyed
PYQ 22

A modulated signal is $$y\left( t \right)\, = \,\,\,\,\,\,\,\,\,m\left( t \right)\,\cos \left( {40000\pi t} \right),$$ where the baseband signal $$m\left( t \right)\,$$ has frequen...

Signals and Systems·INTEGER
PYQ 23

A thin P-type silicon sample is uniformly illuminated with light which generates excess carriers. The recombination rate is directly proportional to

Electronic Devices and Vlsi·MCQ·easy·✓ keyed
PYQ 24

At T = 300 K, the hole mobility of a semiconductor $$\mu_p\;=500\;cm^2/V-s$$ and $$\frac{kT}q\;=\;26\;mV$$.The hole diffusion constant D p in cm 2 /s is__________.

Electronic Devices and Vlsi·NAT·easy
PYQ 25

The slope of the I D vs. V GS curve of an n-channel MOSFET in linear region is 10 -3 $${\Omega ^{ - 1}}$$ at V DS = 0.1V. For the same device, neglecting channel length modulation,...

Electronic Devices and Vlsi·NAT·medium
PYQ 26

In MOSFET fabrication, the channel length is defined during the process of

Electronic Devices and Vlsi·MCQ·easy·✓ keyed
PYQ 27

An ideal MOS capacitor has boron doping concentration of 10 15 cm -3 in the substrate. When a gate voltage is applied, a depletion region of width 0.5 $$\mu m$$ is formed with a su...

Electronic Devices and Vlsi·NAT·medium
PYQ 28

For an all-pass system H(z)= $${{({z^{ - 1}} - b)} \over {(1 - a{z^{ - 1}})}}$$ where $$\left| {H({e^{ - j\omega }})} \right| = \,1$$ , for all $$\omega $$. If Re (a) $$ \ne $$ 0,$...

Signals and Systems·MCQ·medium·✓ keyed
PYQ 29

The z-transform of the sequence x$$\left[ n \right]$$ is given by x(z)= $${1 \over {{{(1 - 2{z^{ - 1}})}^2}}}$$ , with the region of convergence $$\left| z \right| > 2$$. Then, $$x...

Signals and Systems·NAT·easy
PYQ 30

Let $${H_1}(z) = {(1 - p{z^{ - 1}})^{ - 1}},{H_2}(z) = {(1 - q{z^{^{ - 1}}})^{ - 1}}$$ , H(z) =$${H_1}(z)$$ +r $${H_2}$$. The quantities p, q, r are real numbers. Consider , p=$${1...

Signals and Systems·NAT·medium
PYQ 31

The phase response of a passband waveform at receiver is given by $$\varphi \,(f) = - 2\,\pi \,\alpha \,(f - {f_c}) - \,2\pi \beta \,{f_c}$$ where $${f_c}$$ is the centre frequency...

Signals and Systems·MCQ·easy·✓ keyed
PYQ 32

Let h(t) denote the impulse response of a casual system with transfer function $${1 \over {s + 1}}$$. Consider the following three statements. S1: The system is stable. S2: $${{h\l...

Signals and Systems·STMT·medium·✓ keyed
PYQ 33

The input $$ - 3{e^{2t}}\,\,u\left( t \right)$$, where u(t) is the unit step function$$\, {{s - 2} \over {s + 3}}$$. If the initial value of the output is -2, then the value of the...

Signals and Systems·NAT·medium
PYQ 34

Let $$\,x\,\,\left( t \right)\,\,\, = \,\,\,\cos \,\,\,\left( {10\pi t} \right)\,\, + \,\,\cos \,\,\left( {30\pi t} \right)$$ be sampled at $$20\,\,\,Hz$$ and reconstructed using a...

Signals and Systems·MCQ·medium·✓ keyed
PYQ 35

Consider an FM signal $$f\left(t\right)\;=\;\cos\left[2{\mathrm{πf}}_\mathrm c\mathrm t\;+\;{\mathrm\beta}_1\sin\;2{\mathrm{πf}}_1\mathrm t\;+\;{\mathrm\beta}_2\sin\;2{\mathrm{πf}}...

Communications·MCQ·easy·✓ keyed
PYQ 36

Given the vector $$$\mathrm A=\left(\cos\;\mathrm x\right)\left(\sin\;\mathrm y\right)\;{\widehat{\mathrm a}}_\mathrm x\;+\;\left(\sin\;\mathrm x\right)\left(\cos\;\mathrm y\right)...

Electromagnetics·NAT·easy

Set 4

PYQ 1

Match column A with column B. Column 1. Point electromagnetic source 2. Dish antenna 3. Yagi-Uda antenna Column P. Highly directional Q. End fire R. Isotropic

Electromagnetics·MTF·easy·✓ keyed
PYQ 2

For a right angled triangle, if the sum of the lengths of the hypotenuse and a side is kept constant, in order to have maximum area of the triangle, the angle between the hypotenus...

Engineering Mathematics·MCQ·medium·✓ keyed
PYQ 3

The unilateral Laplace transform of $$f(t)$$ is $${1 \over {{s^2} + s + 1}}$$. Which one of the following is the unilateral Laplace transform of $$g\left( t \right) = t.f\left( t \...

Engineering Mathematics·MCQ·easy·✓ keyed
PYQ 4

Consider a transfer function $$G_p\left(s\right)\;=\;\frac{ps^2+3ps\;-2}{s^2+\left(3+p\right)s\;+\left(2-p\right)}$$ with 'p' a positive real parameter. The maximum value of 'p' un...

Control Systems·NAT·easy
PYQ 5

Parcels from sender $$S$$ to receiver $$R$$ pass sequentially through two post - offices. Each post - office has a probability $${1 \over 5}$$ of losing an incoming parcel, indepen...

Engineering Mathematics·NAT·medium
PYQ 6

For a given sample-and-hold circuit, if the value of the hold capacitor is increased, then

Analog Circuits·MCQ·easy·✓ keyed
PYQ 7

Given $$\,\,\overrightarrow F = z\widehat a{}_x + x\widehat a{}_y + y\widehat a{}_z.\,\,$$ If $$S$$ represents the portion of the sphere $${x^2} + {y^2} + {z^2} = 1$$ for $$\,z \ge...

Engineering Mathematics·NAT·medium
PYQ 8

The directional derivative of $$f\left( {x,y} \right) = {{xy} \over {\sqrt 2 }}\left( {x + y} \right)$$ at $$(1, 1)$$ in the direction of the unit vector at an angle of $${\pi \ove...

Engineering Mathematics·NAT·medium
PYQ 9

With initial values $$\,\,\,y\left( 0 \right) = y'\left( 0 \right) = 1,\,\,\,$$ the solution of the differential equation $$\,\,{{{d^2}y} \over {d{x^2}}} - 4{{dy} \over {dx}} + 4y...

Engineering Mathematics·NAT·easy
PYQ 10

If calls arrive at a telephone exchange such that the time of arrival of any call is independent of the time of arrival of earlier of future calls, the probability distribution fun...

Engineering Mathematics·MCQ·easy·✓ keyed
PYQ 11

The series $$\sum\limits_{n = 0}^\infty {{1 \over {n!}}\,} $$ converges to

Engineering Mathematics·MCQ·easy·✓ keyed
PYQ 12

If the emitter resistance in a common-emitter voltage amplifier is not bypassed, it will

Analog Circuits·MCQ·easy·✓ keyed
PYQ 13

A BJT in common-base configuration is used to amplify a signal received by a $$50\,\Omega $$ antena. Assume kT/q = 25 mV. The value of the collector bias current ( in mA ) required...

Analog Circuits·NAT·easy
PYQ 14

If calls arrive at a telephone exchange such that the time of arrival of any call is independent of the time of arrival of earlier or future calls, the probability distribution fun...

Communications·MCQ·easy·✓ keyed
PYQ 15

If $$\overrightarrow{\mathrm E}=-\left(2\mathrm y^2\;-3\mathrm{yz}^2\right)\widehat{\mathrm x}\;-\left(6\mathrm{xy}^2-3\mathrm{xz}^2\right)\widehat{\mathrm y}+\left(6\mathrm{xyz}\r...

Electromagnetics·MCQ·easy·✓ keyed
PYQ 16

An M - level PSK modulation scheme is used to transmit independent binary digits over a band-pass channel with bandwidth 100 kHz. The bit rate is 200 kbps and the system characteri...

Communications·NAT·medium
PYQ 17

Consider a communication scheme where the binary valued signal X satisfies P{X = + 1} = 0.75 and P {X = - 1} = 0.25. The received signal Y = X + Z, where Z is a Gaussian random var...

Communications·MCQ·medium·✓ keyed
PYQ 18

Consider a discrete-time channel Y = X + Z, where the additive noise Z is signal- dependent. In particular, given the trasmitted symbol $$X\, \in \,\{ \, - \,a,\,\, + \,a\} $$ at a...

Communications·MCQ·medium·✓ keyed
PYQ 19

For an antenna radiating in free space, the electric field at a distance of 1 km is found to be 12 m V/m. Given that intrinsic impedance of the free space is 120$$\pi \Omega $$, th...

Electromagnetics·NAT·medium
PYQ 20

Let $$X$$ be a zero mean unit variance Gaussian random variable. $$E\left[ {\left| X \right|} \right]$$ is equal to ______

Engineering Mathematics·NAT·medium
PYQ 21

An 8085 microprocessor executes “STA 1234H” with starting address location 1FFEH (STA copies the contents of the Accumulator to the 16-bit address location). While the instruction...

Microprocessors·MCQ·medium·✓ keyed
PYQ 22

If $$a$$ and $$b$$ are constants, the most general solution of the differential equation $$\,{{{d^2}x} \over {d{t^2}}} + 2{{dx} \over {dt}} + x = 0$$ is

Engineering Mathematics·MCQ·easy·✓ keyed
PYQ 23

The state transition matrix $$\phi \left( t \right)$$ of a system $$$\left[ {\matrix{ {\mathop {{x_1}}\limits^ \bullet } \cr {\mathop {{x_2}}\limits^ \bullet } \cr } } \right] = \l...

Control Systems·MCQ·easy·✓ keyed
PYQ 24

The magnitude of the gradient for the function $$f\left( {x,y,z} \right) = {x^2} + 3{y^2} + {z^3}\,\,$$ at the point $$(1,1,1)$$ is _________.

Engineering Mathematics·NAT·easy
PYQ 25

In a Bode magnitude plot, which one of the following slopes would be exhibited at high frequencies by a 4 th order all-pole system?

Control Systems·MCQ·easy·✓ keyed
PYQ 26

A Fourier transform pair is given by $${\left( {{2 \over 3}} \right)^n}$$ u $$\left[ {n + 3} \right]\,\mathop \Leftrightarrow \limits^{FT} \,{{A{e^{ - j6\pi f}}} \over {1 - \left(...

Signals and Systems·NAT·medium
PYQ 27

The cut-off wavelength (in µm) of light that can be used for intrinsic excitation of a semiconductor material of bandgap E g = 1.1 eV is ________.

Electronic Devices and Vlsi·NAT·easy
PYQ 28

Consider a silicon sample doped with N D = 1×10 15 /cm 3 donor atoms. Assume that the intrinsic carrier concentration n i = 1.5×10 10 /cm 3 . If the sample is additionally doped wi...

Electronic Devices and Vlsi·NAT·easy
PYQ 29

Consider two BJT's biased at the same collector current with area A 1 = 0.2 μm × 0.2 μm and A 2 = 300 μm × 300 μm. Assuming that all other device parameters are identical, kT/q = 2...

Electronic Devices and Vlsi·NAT·medium
PYQ 30

The sequence x $$\left[ n \right]$$ = $${0.5^n}$$ u[n], where u$$\left[ n \right]$$ is the unit step sequence, is convolved with itself to obtain y $$\left[ n \right]$$ . Then $$\s...

Signals and Systems·NAT·easy
PYQ 31

A stable linear time invariant (LTI) system has a transfer function H(s) = $${1 \over {{s^2} + s - 6}}$$. To make this system casual it needs to be cascaded with another LTI system...

Signals and Systems·MCQ·medium·✓ keyed
PYQ 32

The unilateral Laplace transform of F(t) is $${1 \over {{s^2} + s + 1}}$$. Which one of the following is the unilateral Laplace transform of g(t) = $$t \cdot f\left( t \right)$$

Signals and Systems·MCQ·easy·✓ keyed
PYQ 33

A real - values signal x(t) limited to the frequency band $$\left| f \right| \le {W \over 2}$$ is passed through a linear time invariant system whose frequency response is $$H(f) =...

Signals and Systems·MCQ·easy·✓ keyed
PYQ 34

A casual LTI system has zero initial conditions and impulse response h(t). Its input x(t) and output y(t) are related through the linear constant - coefficient differential equatio...

Signals and Systems·NAT·medium
PYQ 35

The N-point DFT X of a sequence x[n] 0 ≤ n ≤ N − 1 is given by $$X\left[ k \right] = {1 \over {\sqrt N }}\,\,\sum\limits_{n = 0}^{N - 1} x \,[n\,]e{\,^{ - j{{2\pi } \over N}nk}}$$,...

Signals and Systems·MCQ·medium·✓ keyed