Recent activity - GO Electrical

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1

GATE2016-1-50
A single-phase full-bridge voltage source inverter $(VSI)$ is fed from a $300 V$ battery. A pulse of $120^\circ$ duration is used to trigger the appropriate devices in each half-cycle. The rms value of the fundamental component of the output voltage, in volts, is $234$ $245$ $300$ $331$

edited Oct 3 in Electrical Circuits by jothee (1.4k points)

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GATE2016-1-51
A single-phase transmission line has two conductors each of $10$ mm radius. These are fixed at a center-to-center distance of $1$ m in a horizontal plane. This is now converted to a three-phase transmission line by introducing a third conductor of the same ... $D$, in meters, is _________.

edited Oct 3 in Power Systems by jothee (1.4k points)

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GATE2016-1-43
A single-phase thyristor-bridge rectifier is fed from a $230 V, 50 Hz$, single-phase $AC$ mains. If it is delivering a constant $DC$ current of $10 A$, at firing angle of $30^\circ$, then value of the power factor at $AC$ mains is $0.87$ $0.9$ $0.78$ $0.45$

edited Oct 3 in new by jothee (1.4k points)

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4

GATE2016-1-42
If the star side of the star-delta transformer shown in the figure is excited by a negative sequence voltage, then $V_{AB}$ leads $V_{ab}$ by $60^\circ$ $V_{AB}$ lags $V_{ab}$ by $60^\circ$ $V_{AB}$ leads $V_{ab}$ by $30^\circ$ $V_{AB}$ lags $V_{ab}$ by $30^\circ$

edited Oct 3 in Power Systems by jothee (1.4k points)

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GATE2016-1-37
A $2$-bit flash Analog to Digital Converter $(ADC)$ is given below. The input is $0 \leq V_{IN} \leq 3$ Volts. The expression for the $LSB$ of the output $B_{o}$ as a Boolean function of $X_{2}, X_{1}$, and $X_{0}$ ... $X_{0}\left[X_{2} \oplus X_{1}\right] \\$ $\overline{X_{0}}\left[X_{2} \oplus X_{1}\right]$

edited Oct 3 in Analog and Digital Electronics by jothee (1.4k points)

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GATE2016-1-41
A $30 MVA$, $3$-phase, $50 Hz$, $13.8 kV$, star-connected synchronous generator has positive, negative and zero sequence reactances, $15\%$, $15\%$ and $5\%$ respectively. A reactance $(X_{n})$ is connected between the neutral of the generator and ground. A ... $X_{n}$ (in p.u.) that will limit the positive sequence generator current to $4270 \: A$ is ________.

edited Oct 3 in Power Systems by jothee (1.4k points)

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7

GATE2016-1-33
Given the following polynomial equation $s^{3}+5.5 s^{2}+8.5s+3=0$ the number of roots of the polynomial, which have real parts strictly less than $−1$, is ________.

edited Oct 3 in Linear Algebra by jothee (1.4k points)

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GATE2016-1-31
Consider the following state-space representation of a linear time-invariant system. $x(t)=\begin{pmatrix} 1&0 \\ 0&2 \end{pmatrix} x(t), y(t)= c^{T} x(t), c =\begin{pmatrix} 1& \\ 1& \end{pmatrix} \text {and } x(0)= \begin{pmatrix} 1& \\ 1& \end{pmatrix}$ The value of $y(t)$ for $t =\log_{e} 2$ is __________.

edited Oct 3 in Control Systems by jothee (1.4k points)

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9

GATE2016-1-32
Loop transfer function of a feedback system is $G(s)H(s)=\dfrac{s+3}{s^{2}(s-3)}$. Take the Nyquist contour in the clockwise direction. Then, the Nyquist plot of $G(s) H (s)$ encircles $-1 + j0$ Once in clockwise direction Twice in clockwise direction Once in anticlockwise direction Twice in anticlockwise direction

edited Oct 3 in Control Systems by jothee (1.4k points)

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GATE2016-1-30
Consider the following asymptotic Bode magnitude plot ($\omega$ is in rad/s). Which one of the following transfer functions is best represented by the above Bode magnitude plot? $\dfrac{2s}{(1+0.5s)(1+0.25s)^{2}} \\$ $\dfrac{4(1+0.5s)}{s(1+0.25s)} \\$ $\dfrac{2s}{(1+2s)(1+4s)} \\$ $\dfrac{4s}{(1+2s)(1+4s)^{2}}$

edited Oct 3 in Control Systems by jothee (1.4k points)

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GATE2016-1-27
Let $S=\sum_{n=0}^{\infty} n\alpha^{n}$ where $\mid \alpha \mid < 1$. The value of $\alpha$ in the range $0 < \alpha < 1$, such that $S=2 \alpha$ is _________.

edited Oct 3 in Signals and Systems by jothee (1.4k points)

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12

GATE2016-1-25
If an ideal transformer has an inductive load element at port $2$ as shown in the figure below, the equivalent inductance at port $1$ is $nL \\$ $n^{2}L \\$ $\dfrac{n}{L} \\$ $\dfrac{n^{2}}{L}$

edited Oct 3 in Electrical Machines by jothee (1.4k points)

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13

GATE2016-1-13
In cylindrical coordinate system, the potential produced by a uniform ring charge is given by $\phi = f(r, z)$ where $f$ is a continuous function of $r$ and $z$. Let $\overrightarrow{E}$ be the resulting electric field. Then the magnitude of $\nabla \times \overrightarrow{E}$ Increases with $r$ Is $0$. Is $3$. Decreases with $z$.

edited Oct 3 in Electromagnetic Fields by jothee (1.4k points)

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14

GATE2016-1-11
Consider the following circuit which uses a $2$-to-$1$ multiplexer as shown in the figure below. The Boolean expression for output $F$ in terms of $A$ and $B$ is $A\oplus B$ $\overline{A+B}$ $A+B$ $\overline{A \oplus B}$

edited Oct 3 in Analog and Digital Electronics by jothee (1.4k points)

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GATE2016-1-10
A temperature in the range of $−40 ^\circ C$ to $55^\circ C$ is to be measured with a resolution of $0.1^\circ C$. The minimum number of $ADC$ bits required to get a matching dynamic range of the temperature sensor is $8$ $10$ $12$ $14$

edited Oct 3 in new by jothee (1.4k points)

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16

GATE2016-1-9
The value of $\int_{-\infty}^{+\infty} e^{-t} \delta (2t-2){d}t$, where $\delta (t)$ is the Dirac delta function, is $\dfrac{1}{2e} \\$ $\dfrac{2}{e} \\$ $\dfrac{1}{e^{2}} \\$ $\dfrac{1}{2e^{2}}$

edited Oct 3 in Calculus by jothee (1.4k points)

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17

GATE2016-1-7
The phase cross-over frequency of the transfer function $G(s)=\dfrac{100}{(s+1)^{3}}$ in rad/s is $\sqrt{3} \\$ $\dfrac{1}{\sqrt{3}} \\$ $3 \\$ $3\sqrt{3}$

edited Oct 3 in Control Systems by jothee (1.4k points)

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18

GATE2016-1-6
The transfer function of a system is $\dfrac{Y(s)}{R(s)}=\dfrac{s}{s+2}$. The steady state output $y(t)$ is $A \cos (2t + \phi)$ for the input $\cos (2t)$. The values of $A$ and $\phi$ respectively are $\dfrac{1}{\sqrt{2}}, -45^\circ$ $\dfrac{1}{\sqrt{2}}, +45^\circ$ $\sqrt{2}, -45^\circ$ $\sqrt{2}, +45^\circ$

edited Oct 3 in Control Systems by jothee (1.4k points)

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19

GATE2016-1-5
The value of the integral $\oint _{c}\dfrac{2z+5}{\left ( z-\dfrac{1}{2} \right ) \left (z^{2} -4z+5 \right )}dz$ over the contour $\mid z \mid=1$, taken in the anti-clockwise direction, would be $\dfrac{24 \pi i}{13} \\$ $\dfrac{48 \pi i}{13} \\$ $\dfrac{24}{13} \\$ $\dfrac{12}{13}$

edited Oct 3 in Differential Equations by jothee (1.4k points)

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20

GATE2016-1-4
A function $y(t)$, such that $y(0)=1$ and $y(1)=3e^{-1}$, is a solution of the differential equation $\dfrac{d^{2}y}{dt^{2}}+2\dfrac{dy}{dt}+y=0$. Then $y(2)$ is $5e^{-1}$ $5e^{-2}$ $7e^{-1}$ $7e^{-2}$

edited Oct 3 in Differential Equations by jothee (1.4k points)

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21

GATE2016-1-3
The Laplace Transform of $f(t)=e^{2t} \sin (5t)(ut)$ is $\dfrac{5}{s^{2}-4s+29} \\ $ $\dfrac{5}{s^{2}+5} \\ $ $\dfrac{s-2}{s^{2}-4s+29} \\$ $\dfrac{5}{s +5}$

edited Oct 3 in Signals and Systems by jothee (1.4k points)

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22

GATE2016-1-GA-10
Choose the correct expression for $f(x)$ given in the graph. $f(x) = 1 - \mid x - 1 \mid $ $f(x) = 1 + \mid x - 1 \mid $ $f(x) = 2 - \mid x - 1 \mid $ $f(x) = 2 + \mid x - 1 \mid $

edited Oct 3 in Calculus by jothee (1.4k points)

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23

GATE2016-1-GA-8
All hill-stations have a lake. Ooty has two lakes. Which of the statement(s) below is/are logically valid and can be inferred from the above sentences? Ooty is not a hill-station. No hill-station can have more than one lake. (i) only (ii) only Both (i) and (ii) Neither (i) nor (ii)

edited Oct 3 in Numerical Ability by jothee (1.4k points)

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24

GATE2016-1-GA-7
Computers were invented for performing only high-end useful computations. However, it is no understatement that they have taken over our world today. The internet, for example, is ubiquitous. Many believe that the internet itself is an unintended consequence of the original invention ... internet are both intended inventions (i) only (ii) only Both (i) and (ii) Neither (i) nor (ii)

edited Oct 3 in Numerical Ability by jothee (1.4k points)

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25

GATE2016-1-GA-6
Among $150$ faculty members in an institute, $55$ are connected with each other through Facebook$^®$ and $85$ are connected through WhatsApp$^®$. $30$ faculty members do not have Facebook$^®$ or WhatsApp$^®$ accounts. The number of faculty members connected only through Facebook$^®$ accounts is _________. $35$ $45$ $65$ $90$

edited Oct 3 in Numerical Ability by jothee (1.4k points)

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26

GATE2016-1-GA-5
In a quadratic function, the value of the product of the roots $(\alpha, \beta)$ is $4$. Find the value of $\dfrac{\alpha^{n}+\beta^{n}}{\alpha^{-n}+\beta^{-n}}$ $n^{4}$ $4^{n}$ $2^{2n-1}$ $4^{n-1}$

edited Oct 3 in Linear Algebra by jothee (1.4k points)

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27

GATE2015-2-11
The operational amplifier shown in the figure is ideal. The input voltage (in Volt) is $V_{i} = 2 \sin(2\pi \times 2000t)$. The amplitude of the output voltage $V_{o}$ (in Volt) is ________.

edited Oct 3 in Control Systems by jothee (1.4k points)

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28

GATE2015-2-39
The saturation voltage of the ideal op-amp shown below is $\pm 10$ V. The output voltage $v_{o}$ of the following circuit in the steady-state is Square wave of period $0.55$ ms. Triangular wave of period $0.55$ ms. square Square wave of period $0.25$ ms. Triangular wave of period $0.25$ ms

edited Oct 3 in new by jothee (1.4k points)

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29

GATE2015-2-33
In the given rectifier, the delay angle of the thyristor $T_{1}$ measured from the positive going zero crossing of $V_{s}$ is $30^\circ$. If the input voltage $V_{s}$ is $100 \sin(100 \pi t) V$, the average voltage across $R$ (in Volt) under steady-state is _________.

edited Oct 3 in Analog and Digital Electronics by jothee (1.4k points)

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30

GATE2015-2-9
Two semi-infinite dielectric regions are separated by a plane boundary at $y = 0$. The dielectric constants of region $1 (y < 0)$ and region $2 (y > 0)$ are $2$ and $5$, respectively. Region $1$ has uniform electric field $\overrightarrow{E}=3\hat{a}_{x}+4\hat{a}_{y}+2\hat{a}_{z}$ ... $3\hat{a}_{x}+10\hat{a}_{y}+0.8\hat{a}_{z}$

edited Oct 3 in new by jothee (1.4k points)

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31

GATE2015-2-GA-9
If the list of letters, $P, R, S, T, U$ is an arithmetic sequence, which of the following are also in arithmetic sequence? $2P, 2R, 2S, 2T, 2U$ $P-3, R-3, S-3, T-3, U-3$ $P^{2}, R^{2}, S^{2}, T^{2}, U^{2}$ $I$ only $I$ and $II$ $II$ and $III$ $I$ and $III$

edited Oct 3 in Numerical Ability by jothee (1.4k points)

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32

GATE2015-2-54
An open loop transfer function $G(s)$ of a system is $G(s)=\dfrac{k}{s(s+1)(s+2)}$ For a unity feedback system, the breakaway point of the root loci on the real axis occurs at, $−0.42$ $−1.58$ $−0.42$ and $−1.58$ None of the above

edited Oct 3 in new by jothee (1.4k points)

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33

GATE2015-2-53
The unit step response of a system with the transfer function $G(s)=\dfrac{1-2s}{1+s}$ is given by which one of the following waveforms?

edited Oct 3 in new by jothee (1.4k points)

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34

GATE2015-2-52
The following discrete-time equations result from the numerical integration of the differential equations of an un-damped simple harmonic oscillator with state variables $x$ and $y$. The integration time step is $h$. $\dfrac{x_{k+1}-x_{k}}{h}=y_{k}$ ... $0 < h <\dfrac{1}{2\pi} \\$ The system is stable for $\dfrac{1}{2\pi}<h<\dfrac{1}{\pi}$

edited Oct 3 in new by jothee (1.4k points)

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35

GATE2015-2-50
A $220$ V, $3$-phase, $4$-pole, $50$ Hz inductor motor of wound rotor type is supplied at rated voltage and frequency. The stator resistance, magnetizing reactance, and core loss are negligible. The maximum torque produced by the rotor is $225\%$ of ... of external resistance (in Ohm) which must be inserted in a rotor phase if the maximum torque is to occur at start is _________.

edited Oct 3 in new by jothee (1.4k points)

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36

GATE2015-2-47
A three-winding transformer is connected to an $AC$ voltage source as shown in the figure. The number of turns are as follows: $N_{1} = 100, N_{2} = 50, N_{3} = 50$ ... $1\angle 90^{\circ}$ $1\angle 270^{\circ}$ $4\angle 90^{\circ}$ $4\angle 270^{\circ}$

edited Oct 3 in new by jothee (1.4k points)

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37

GATE2015-2-40
The incremental costs (in Rupees/MWh) of operating two generating units are functions of their respective powers $P_{1}$ and $P_{2}$ in $MW$, and are given by $\dfrac{dC_{1}}{dP_{1}}=0.2P_{1}+50$ $\dfrac{dC_{2}}{dP_{2}}=0.24P_{2}+40$ ... Rs/MWh and $dC_{2}/dP_{2} = 68.8$ Rs/MWh. If the generations are rescheduled to minimize the total cost, then $P_{2}$ is ________.

edited Oct 3 in new by jothee (1.4k points)

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38

GATE2015-2-38
A Boolean function $f(A, B, C, D) = \prod (1,5,12,15)$ is to be implemented using an $8 \times 1$ multiplexer ($A$ is $MSB$). The inputs $ABC$ are connected to the select inputs $S_{2} S_{1} S_{0}$ of the multiplexer respectively. Which one of the following options gives the correct ... $D, 1, D, 1, 1, 1, \overline{D}, D$ $\overline{D}, 0, \overline{D}, 0, 0, 0,D, \overline{D}$

edited Oct 3 in new by jothee (1.4k points)

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39

GATE2015-2-36
Two semi-infinite conducting sheets are placed at right angles to each other as shown in the figure. A point charge of $+Q$ is placed at a distance of $d$ from both sheets. The net force on the charge is $\dfrac{Q^{2}}{4\pi \in_{0}} \frac{Q}{d^{2}}$, where $K$ is given by $0 \\$ ... $\dfrac{1-2\sqrt{2}}{8\sqrt{2}} \hat{t}+\dfrac{1-2\sqrt{2}}{8\sqrt{2}} \hat{j}$

edited Oct 3 in new by jothee (1.4k points)

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40

GATE2015-2-45
A symmetrical square wave of $50\%$ duty cycle has amplitude of $\pm15$ V and time period of $0.4\pi$ ms. This square wave is applied across a series $RLC$ circuit with $R = 5 \Omega$, $L = 10$ mH, and $C = 4 \mu F$. The amplitude of the $5000$ rad/s component of the capacitor voltage (in Volt) is ______.

edited Oct 3 in new by jothee (1.4k points)