GATE EE
$$ \text { Assuming ideal op-smps, the circuit represents is } $$


In the circuit, shown below, if the values of $R$ and $C$ are very large, the form of the output voltage for a very high frequency square wave input, is best represented by

The op-amps in the following circuit are ideal. The voltage gain of the circuit is ___________. (Round off to the nearest integer)

Selected data points of the step response of a stable first-order linear time-invariant (LTI) system are given below. The closest value of the time-constant, in sec, of the system is
$$ \begin{array}{|l|c|c|c|c|c|} \hline \text { Time (sec) } & 0.6 & 1.6 & 2.6 & 10 & \infty \\ \hline \text { Output } & 0.78 & 1.65 & 2.18 & 2.98 & 3 \\ \hline \end{array} $$The Nyquist plot of a strictly stable $G(s)$ having the numerator polynomial as $(s-3)$ encircles the critical point -1 once in the anti-clockwise direction. Which one of the following statements on the closed-loop system shown in figure, is correct?

The open-loop transfer function of the system shown in the figure, is
$$ G(s)=\frac{K s(s+2)}{(s+5)(s+7)} $$
For $K \geq 0$, which of the following real axis point(s) is/are on the rool locus?

$$ \text { Let } G(s)=\frac{1}{(s+1)(s+2)} \text {. Then the closed-loop system shown in the figure below, is } $$


A Boolean function is given as
$$ f=(\bar{u}+\bar{v}+\bar{w}+\bar{x}) \cdot(\bar{u}+\bar{v}+\bar{w}+x) \cdot(\bar{u}+v+\bar{w}+\bar{x}) \cdot(\bar{u}+v+\bar{w}+x) $$
The simplified form of this function is represented by
$$ \text { The I-V characteristics of the elements between the nodes } X \text { and } Y \text { is best depicted } $$

A nullator is defined as a circuit element where the voltage across the device and the current through the device are both zero. A series combination of a nullator and a resistor of value, $R$, will behave as a
The input voltage $v(t)$ and current $i(t)$ of a converter are given by, $v(t)=300 \sin (\omega t) \mathrm{V}$
$$ i(t)=10 \sin \left(\omega t-\frac{\pi}{6}\right)+2 \sin \left(3 \omega t+\frac{\pi}{6}\right)+\sin \left(5 \omega t+\frac{\pi}{2}\right) A $$
where, $\omega=2 \pi \times 50 \mathrm{rad} / \mathrm{s}$. The input power factor of the converter is closest to
The transformer connection given in the figure is part of a balanced 3-phase circuit where the phase sequence is "abc". The primary to secondary turns ratio is $2: 1$. If ( $I_a+I_b+I_c=0$ ), then the relationship between $l_A$ and $l_{\text {ad }}$ will be



The maximum percentage error in the equivalent resistance of two parallel connected resistors of $100 \Omega$ and $900 \Omega$ with each having a maximum $5 \%$ error is ____________\%. (Round off to nearest integer value)

The operating region of the developed torque ( $T_{\mathrm{em}}$ ) and speed ( $\omega$ ) of an induction motor drive is given by the shaded region OQRE in the figure. The load torque $\left(T_L\right)$ characteristic is also shown. The motor drive moves from the initial operating point O to the final operating point S . Which one of the following trajectories will take the shortes time?

A 3-phase, $400 \mathrm{~V}, 4$ pole, 50 Hz star connected induction motor has the following parameters referred to the stator :
$$ R_r^{\prime}=1 \Omega, X_S=X_r^{\prime}=2 \Omega $$
Stator resistance, magnetizing reactance and core loss of the motor are neglected. The motor is run with constant V/f control from a drive. For maximum starting torque, the voltage and frequency output, respectively, from the drive, is closest to,
Which one of the following figures represents the radial electric field distribution $E_R$ caused by a spherical cloud of electrons with a volume charge density. $\rho=-3 \rho_0$ for $0 \leq R \leq a$ (both $\rho_0, a$ are positive and $R$ is the radial distance) and $\rho=0$ for $R>a$ ?
An air filled cylindrical capacitor (capacitance $C_0$ ) of length $L$, with $a$ and $b$ as its inner and outer radii, respectively, consists of two coaxial conducting surfaces. Its crosssectional view is shown in Figure (i). In order to increase the capacitance, a dielectric material of relative permittivity $\varepsilon_r$ is inserted inside $50 \%$ of the annular region as shown in figure (ii). The value of $\varepsilon_r$ for which the capacitance of the capacitor in figure (ii), becomes $5 C_0$ is

The relationship between two variables $x$ and $y$ is given by $x+p y+q=0$ and is shown in the figure. Find the values of $p$ and $q$.
Note: The figure shown is representative.

Consider the set $S$ of points $(x, y) \in R^2$ which minimize the real valued function
$$ f(x, y)=(x+y-1)^2+(x+y)^2 $$
Which of the following statements is true about the set $S$ ?
Let $A=\left[\begin{array}{ccc}1 & 1 & 1 \\ -1 & -1 & -1 \\ 0 & 1 & -1\end{array}\right]$ and $b=\left[\begin{array}{c}1 / 3 \\ -1 / 3 \\ 0\end{array}\right]$, then the system of linear equations $A x=b$ has
Let $P=\left[\begin{array}{ccc}2 & 1 & 0 \\ -1 & 0 & 0 \\ 0 & 0 & 1\end{array}\right]$ and let $I$ be the identity matrix. Then $P^2$ is equal to
Consider discrete random variable $X$ and $Y$ with probabilities as follows:
$$ \begin{aligned} & P(X=0 \text { and } Y=0)=\frac{1}{4} \\ & P(X=1 \text { and } Y=1)=\frac{1}{8} \\ & P(X=0 \text { and } Y=1)=\frac{1}{2} \\ & P(X=1 \text { and } Y=1)=\frac{1}{8} \end{aligned} $$
Given $X=1$, the expected value of $Y$ is
Let $X$ and $Y$ be continuous random variables with probability density functions $P_X(x)$ and $P_Y(y)$, respectively. Further, let $Y=X^2$ and $P_X(x)=\left\{\begin{array}{cc}1, & x \in(0,1] \\ 0, & \text { otherwise }\end{array}\right.$.
Which one of the following options is correct?Let $a_R$ be the unit radial vector in the spherical co-ordinate system. For which of the following value(s) of $n$, the divergence of the radial vector field $f(R)=a_R \frac{1}{R^n}$ is independent of $R$ ?

The 3-phase modulating waveforms $\left(v_a(t), v_b(t), v_c(t)\right)$, used in sinusoidal PWM in a voltage source inverter (VSI) are
$$ \begin{aligned} & v_a(t)=0.8 \sin (\omega t) \vee \\ & v_b(t)=0.8 \sin \left(\omega t-\frac{2 \pi}{3}\right) \vee \\ & v_c(t)=0.8 \sin \left(\omega t+\frac{2 \pi}{3}\right) \vee \end{aligned} $$
where $\omega=2 \pi \times 40 \mathrm{rad} / \mathrm{s}$ is the fundamental frequency. The modulating waveforms are compared with a 10 kHz triangular carrier whose magnitude varies between +1 and -1 . The VSI has a DC link voltage of 600 V and feeds a star connected motor. The per phase fundamental RMS motor voltage in volts is closest to
An ideal sinusoidal voltage source $v(t)=230 \sqrt{2} \sin (2 \pi \times 50 t) \vee$ feeds an ideal inductor $L$ through an ideal SCR with firing angle $\alpha=0^{\circ}$. If $L=100 \mathrm{mH}$, then the peak of the inductor current, in ampere, is closest to

In the following circuit, the average voltage
$$ V_0=400\left(1+\frac{\cos \alpha}{3}\right) V $$
where $\alpha$ is the firing angle. If the power dissipated in the resistor is 64 W , then the closest value of $\alpha$ in degrees is


During a power failure, a domestic household uninterruptible power supply (UPS) supplies AC power to a limited number of lights and fans in various rooms. As per a NewtonRaphson load-flow formulation, the UPS would be represented as a
The bus impedance matrix of a 3-bus system (in pu) is
$$ Z_{\text {bus }}=\left[\begin{array}{lll} j 0.059 & j 0.061 & j 0.038 \\ j 0.061 & j 0.093 & j 0.066 \\ j 0.038 & j 0.066 & j 0.110 \end{array}\right] $$
A symmetrical fault (through a fault impedance of $j 0.007$ p.u.) occurs at bus 2 . Neglecting pre-fault loading conditions, the voltage at bus 1 , during the fault is __________ p.u. (round off to three decimal places).
In the system shown below, the generator was initially supplying power to the grid. A temporary LLLG bolted fault occurs at F very close to circuit breaker-1. The circuit breakers open to isolate the line. The fault self-clears. The circuit breakers reclose and restore the line. Which one of the following diagrams best indicates the rotor accelerating and decelerating areas?

Consider a discrete-time linear time-invariant (LTI) system, $\boldsymbol{S}$, where
$$ y[n]=S\{x(\mathrm{n})\} $$
$$Let\,\,\,\, S\{\delta[n]\}=\left\{\begin{array}{lc} 1, & n \in\{0,1,2\} \\ 0, & \text { otherwise } \end{array}\right. $$
where $\delta[n]$ is the discrete-time unit impulse function. For an input signal $x[n]$, the output $y[n]$ is
Consider a continuous-time signal
$$ x(t)=-t^2\{u(t+4)-u(t-4)\} $$
where $u(t)$ is the continuous-time unit step function. Let $\delta(t)$ be the continuous-time unit impulse function. The value of
$$ \int_{-\infty}^{\infty} x(t) \delta(t+3) d t $$
is
A continuous time periodic signal $x(t)$ is
$$ x(t)=1+2 \cos 2 \pi t+2 \cos 4 \pi t+2 \cos 6 \pi t $$
If $T$ is the period of $x(t)$, then $\frac{1}{T} \int_0^T|x(t)|^2 d t=$________(round off to the nearest integer).
Let continuous-time signals $x_1(t)$ and $x_2(t)$ be
$x_1(t)=\left\{\begin{array}{cc}1, & t \in[0,1] \\ 2-t, & t \in[1,2] \\ 0, & \text { otherwise }\end{array}\right.$
and $x_2(t)=\left\{\begin{array}{cc}t, & t \in[0,1] \\ 2-t, & t \in[1,2] \\ 0, & \text { otherwise }\end{array}\right.$.
$y(t)=x_1(t) * x_2(t)$. Then $\int\limits_{-\infty}^{\infty} y(t) d t$ is :
General Aptitude
Kavya__________go to work yesterday as she________ feeling well. Select the most approrpriate option to complete the above sentence.
Good : Evil : : Genuine : ?
Select the most appropriate option to complete the analogy.
Each row of Column-I has three items and each item is represented by a circle in ColumnII. The arrangement of circles in Column-II represents the relationship among the items in Column-I.
Identify the option that has the most appropriate match between Column-I and ColumnII.
Note: The figure shown are representative.

Identify the option that has the most appropriate sequence such that a coherent paragraph is formed :
(P) It is because deer, like most of the animals that tigers normally prey on, run much faster! It simply means, another day of empty stomach for the big cats.
(Q) Tigers spend most of their life searching for food.
(R) If they trace the scent of deer, tigers follow the trail, chase the deer for a mile or two in the dark, and yet may not catch them.
(S) For several nights, they relentlessely prowl through the forest, hunting for a trail that may lead to their prey.
In the given figure, EF and HJ are coded as 30 and 80, respectively. Which one among the given options is most appropriate for the entires marked (i) and (ii)?
Scores obtained by two students P and Q in seven courses are given in the table below. Based on the information given in the table, which one of the following statements is INCORRECT?
$$ \begin{array}{|l|l|l|l|l|l|l|l|} \hline \mathrm{P} & 22 & 89 & 50 & 45 & 78 & 60 & 39 \\ \hline \mathrm{Q} & 35 & 65 & 60 & 56 & 81 & 45 & 50 \\ \hline \end{array} $$
Spheres of unit diameter are centered at ( $l, m, n$ ) where $l, m$ and $n$ take every possible integer values.
The distance between two spheres is computed from the center of one sphere to the center of the other sphere. For a given sphere, $x$ is the distance to its nearest sphere and $y$ is the distance to its next nearest sphere. The value of $\frac{y}{x}$ is :
In the triangle PQR , the lengths of PT and TR are in the ratio of $3: 2$.
ST is parallel to QR. Two semi-circles are drawn with PS and PQ as diameters, as shown in the figure.
Which one of the following statements is true about the shaded area PQS?
Note: The figure shown is representative.
