GATE 2006 Electrical Engineering
49 questions across 1 session
A $$400V$$, $$50$$ $$Hz,$$ three phase balanced source supplies power to a star connected load whose rating is $$12\,\,\angle 3\,\,kVA,$$ $$0.8$$ $$pf$$ (lag). The rating $$($$in $...
A closed loop system has the characteristic function $$\left( {{s^2} - 4} \right)\left( {s + 1} \right) + K\left( {s - 1} \right) = 0.$$ Its root locus plot against $$K$$ is
A $$4$$ pole, $$50$$ $$Hz,$$ synchronous generator has $$48$$ slots in which a double layer winding is house. Each coil has $$10$$ turns and is short pitched by an angle to $$36$$...
A $$3$$ phase, $$10$$ $$kW$$, $$400$$ $$V,$$ $$4$$ pole, $$50$$ $$Hz$$, star connected induction motor draws $$20$$ A on full load. Its no load and blocked rotor test data are give...
In a biased differential relay the bias is defined as a ratio of
An ideal capacitor is charged to a voltage $${V_0}$$ and connected at $$t=0$$ across an ideal inductor $$L.$$ (The circuit now consists of a capacitor and inductor alone). If we le...
A synchronous generator is feeding a zero power factor (lagging) load at rated current the armature reaction is
The concept of an electrically short, medium, and long line is primarily based on the
Consider the following statements with reference to the equation $$\nabla.\overrightarrow J=-\frac{\partial\rho}{\partial t}$$ 1. This is a point from the continuity equation 2. Di...
A generator is connected through a $$20$$ MVA, $$13.8/138$$ kV step up transformer, to a transmission line. At the receiving end of the line a load is supplied through a step down...
Keeping in view the cost and overall effectiveness, the following circuit breaker is best suited for capacitor bank switching
The Bode magnitude plot of $$H\left( {j\omega } \right) = {{{{10}^4}\left( {1 + j\,\omega } \right)} \over {\left( {10 + j\,\omega } \right){{\left( {100 + j\omega } \right)}^2}}}$...
A generator feeds power to an infinite bus through a double circuit transmission line. A $$3$$ phase fault occurs at the middle point of one of the lines. The infinite bus voltage...
Which of the following statements holds for the divergence of electric and magnetic flux densities?
An HVDC link consists of rectifier, inverter transmission line and other equipments. Which one of the following is true for this link?
For a system with the transfer function $$H\left( s \right) = {{3\left( {s - 2} \right)} \over {{s^3} + 4{s^2} - 2s + 1}},\,\,$$ the matrix $$A$$ in the state space form $$\mathop...
The $$A, B, C, D$$ constant of a $$220$$ $$kV$$ line are: $$A = D = 0.94\,\angle \,10,\,\,\,B = 130\,\angle \,730,\,\,\,C = 0.001\,\angle \,900.\,\,$$ If the sending end voltage of...
A $$300$$ $$kVA$$ transformer has $$95\% $$ efficiency at full load $$0.8$$ $$pf$$ lagging and $$96\% $$ efficiency at half load, unity $$pf.$$ The iron loss $$\left( {{P_i}} \righ...
A generator feeds power to an infinite bus through a double circuit transmission line. A 3 phase fault occurs at the middle point of one of the lines. The infinite bus voltage is 1...
A $$300$$ $$kVA$$ transformer has $$95\% $$ efficiency at full load $$0.8$$ $$pf$$ lagging and $$96\% $$ efficiency at half load, unity $$pf.$$ What is the maximum efficiency (in %...
In transformers, which of the following statements is valid?
A $$400$$ V, $$50$$ Hz, three phase balanced source supplies power to a star connected load whose rating is $$12\sqrt 3 $$ kVA, $$0.8$$ pf(lag). The rating (in kVAR) of the delta c...
Three identical star connected resistors of $$1.0$$ $$p.u$$ are connected to an unbalanced $$3$$ phase supply. The load neutral is isolated. The symmetrical components of the line...
A $$3$$ phase, $$4$$ pole, $$400$$ $$V,$$ $$50$$ $$Hz,$$ star connected induction motor has following circuit parameters $${r_1} = 1.0\Omega ,\,{r_2} = 0.5\Omega ,$$ $${\mkern 1mu}...
A $$220V$$ $$DC$$ machine supplies $$20$$ $$A$$ at $$200V$$ as a generator. The armature resistance is $$0.2$$ ohm. If the machine is now operated as a motor at same terminal volta...
A $$3$$-phase $$4000$$ $$V,$$ $$5$$ $$kW,$$ star connected synchronous motor having an internal reactance of $$10$$ $$ohms$$ is operating at $$50\% $$ load, unity power factor. Now...
The algebraic equation $$F\left( s \right) = {s^5} - 3{s^4} + 5{s^3} - 7{s^2} + 4s + 20$$ $$F\left( s \right) = 0$$ has
Two transformers are to be operated in parallel such that they share load in proportion to their $$kVA$$ ratings. The rating of the first transformer is $$500$$ $$kVA$$ and its $$p...
A $$3$$ $$-$$ phase fully controlled bridge converter with free wheeling diode is fed from $$400$$ $$V$$, $$50$$ $$Hz$$ $$AC$$ source and is operating at a firing angle of $${60^ \...
For a power system the admittance and impedance matrices for the fault studies are as follows. $$$\eqalign{ & {Y_{bus}} = \left[ {\matrix{ { - j8.75} & {j1.25} & {j2.50} \cr {j1.25...
A $$4$$ pole, $$50$$ $$Hz,$$ synchronous generator has $$48$$ slots in which a double layer winding is house. Each coil has $$10$$ turns and is short pitched by an angle to $$36$$...
The Gauss Seidel load flow method has following disadvantages. Tick the incorrect student.
The speed of a $$4$$-pole induction motor is controlled by varying the supply frequency while maintaining the ratio of supply voltage to supply frequency $$(V/f)$$ constant. At rat...
The expression $$V = \int\limits_0^H {\pi {R^2}{{\left( {1 - {h \over H}} \right)}^2}dh\,\,\,} $$ for the volume of a cone is equal to _________.
In a $$DC$$ machine, which of the following statements is true?
The concept of an electricity short, medium and long line is primarily based on the
A solar cell of $$350V$$ is feeding power to an $$ac$$ supply of $$440$$ $$V,$$ $$50$$ $$Hz$$ through a $$3$$- phase fully controlled briodge converter. A large inductance is conne...
For a power system the admittance and impedance matrices for the fault studies are as follows. $$$\eqalign{ & {Y_{bus}} = \left[ {\matrix{ { - j8.75} & {j1.25} & {j2.50} \cr {j1.25...
The discrete-time signal $$$x\left[n\right]\leftrightarrow X\left(z\right)={\textstyle\sum_{n=0}^\infty}\frac{3^n}{2+n}z^{2n}$$$ where $$\leftrightarrow$$ denote a transform-pair r...
$$x(t)$$ is a real valued function of a real variable with period $$T.$$ Its trigonometric. Fourier Series expansion contains no terms of frequency $$\omega = 2\pi \left( {2k} \rig...
A current of $$ - 8 + 6\sqrt 2 \left( {\sin \,\omega t + {{30}^0}} \right)\,\,A$$ is passed though three meters. They are a center zero $$PMMC$$ meter, true $$r.m.s$$ meter and mov...
A variable $$'w'$$ is related to three other variables $$x, y, z$$ as $$w=xy/z.$$ The variables are measured with meters of accuracy$$ \pm $$ $$0.5$$% reading, $$ \pm 1\% $$ of ful...
An energy meter connected to an immersion heater (resistive) operating on an $$AC$$ $$230V,$$ $$50$$ $$Hz,$$ $$AC$$ single phase source reads $$2.3$$ units ($$kWh$$) in $$1$$ hour....
A continuous-time system is described by $$y\left( t \right) = {e^{ - |x\left( t \right)|}},$$ where $$y(t)$$ is the output and $$x(t)$$ is the input. $$y(t)$$ is bounded
A discrete real all pass system has a pole at $$z = 2\angle {30^ \circ };\,$$ it, therefore,
$$y\left[ n \right]$$ denotes the output and $$x\left[ n \right]$$ denotes the input of a discrete-time system given by the difference equation $$y\left[ n \right] - 0.8y\left[ {n...
$${R_1}$$ and $${R_2}$$ are the opposite arms of $${R_3}$$ and $${R_4}$$ of a wheat stone bridge. The source voltage is applied across $${R_1}$$ and $${R_3}$$ under balanced condit...
$$x\left[ n \right] = 0;\,n < - 1,\,n > 0,\,x\left[ { - 1} \right] = - 1,\,x\left[ 0 \right]$$ $$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 2$$ is the input...
A $$200/1$$ current transformer $$(CT)$$ is wound with $$200$$ turns on the secondary on a toroidal core. When it carries a current of $$160$$ $$A$$ on the primary, the ratio and p...