GATE 2003 Electrical Engineering
40 questions across 1 session
Bundled conductors are mainly used in high voltage overhead transmission lines to
A dc series motor driving an electric train faces a constant power load. It is running at rated speed and rated voltage. If the speed has to be brought down to 0.25 p.u. the supply...
Group I lists different applications and Group II lists the motors for these applications. Match the application with the most suitable motor and choose the right combination among...
No-load test on a 3-phase induction motor was conducted at different supply voltages and a plot of input power versus voltage was drawn. This curve was extrapolated to intersect th...
Following are some of the properties of rotating electrical machines P. Stator winding current is dc, rotor-winding current is ac Q. Stator winding current is ac, rotor-winding cur...
A 3-phase Inductor Motor is driving a constant torque load at rated voltage and frequency. If both voltage and frequency are halved, following statements relate to the new conditio...
A single phase induction motor with only the main winding excited would exhibit the following response at synchronous speed
The loop gain $$GH$$ of a closed loop system is given by the following expression $${K \over {s\left( {s + 2} \right)\left( {s + 4} \right)}}.$$ The value of $$K$$ for which the sy...
A stand-alone engine driven Synchronous generator is feeding a partly inductive load. A capacitor is now connected across the load to completely nullify the inductive current. For...
A balanced delta connected load of $$\left( {8 + j6} \right)\Omega $$ per phase is connected to a $$400$$ $$V$$, $$50$$ $$Hz$$, $$3-$$phase supply lines. If the input power factor...
A parallel plate capacitor has an electrode area of $$100$$ $$m{m^2}$$, with a spacing of $$0.1$$ $$mm$$ between the electrodes. The dielectric between the plates is air with a per...
The bus impedance matrix of a $$4$$-bus power system is given by $$${Z_{bus}} = \left[ {\matrix{ {j0.3435} & {j0.2860} & {j0.2723} & {j0.277} \cr {j0.2860} & {j0.3408} & {j0.2586}...
The Boolean expression $$X\overline Y Z + XYZ + \overline X Y\overline Z + \overline X \overline Y Z + XY\overline Z $$ can be simplified to
A control system with certain excitation is governed by the following mathematical equation $$${{{d^2}x} \over {d{t^2}}} + {1 \over 2}{{dx} \over {dt}} + {1 \over {18}}x = 10 + 5{e...
A $$4$$-pole, $$3$$-phase, double layer winding is housed in a $$36$$-slot stator for an $$ac$$ machine with $$60$$ degree phase spread. Coil span is $$7$$ slot pitches. Number of...
The interrupting time of a circuit breaker is the period between the instant of
The ABCD parameters of a $$3$$-phase overhead transmission line are $$\,A = D = 0.9\angle {0^ \circ }.\,\,B = 200\,\angle {90^ \circ }\,\,\Omega \,\,\,$$ and $$\,\,C = 0.95\, \time...
A lead compensator used for a closed loop controller has the following transfer function $${\textstyle{{K\left( {1 + {s \over a}} \right)} \over {\left( {1 + {s \over b}} \right)}}...
A list of relays and the power system components protected by the relays are given in List-$${\rm I}$$ and List-$${\rm II}$$ respectively. Choose the correct match from the four ch...
The following equation defines a separately exited $$dc$$ motor in the form of a differential equation $${{{d^2}\omega } \over {d{t^2}}} + {{B\,d\omega } \over {j\,\,dt}} + {{{K^2}...
Incremental fuel costs (in some appropriate unit) for a power plant consisting of three generating units are $${\rm I}{C_1} = 20 + 0.3\,\,{P_1},\,{\rm I}{C_2} = 30 + 0.4\,\,{P_2},\...
A $$3$$-phase, $$11$$-$$kV$$ generator feeds power to a constant power unity power factor load of $$100$$ $$MW$$ through a $$3$$-phase transmission line. The line-to-line voltage a...
A 20-MVA, 6.6-kV, 3-phase alternator is connected to a 3-phase transmission line. The per unit positive sequence, negative sequence and zero sequence impedance of the alternator ar...
A round rotor generator with internal voltage $${E_1} = 2.0\,\,$$ p.u.and $$\,X = 1.1\,\,$$ p.u. is connected to a round rotor synchronous motor with internal voltage $$\,\,{E_2} =...
A balanced delta connected load of $$\left( {8 + j6} \right)$$ $$\Omega $$ per phase is connected to a $$400V,$$ $$50Hz,$$ $$3-$$ phase supply lines. If the input power factor is t...
A second order system starts with an initial condition of $$\left( {\matrix{ 2 \cr 3 \cr } } \right)$$ without any external input. The state transition matrix for the system is giv...
A control system is defined by the following mathematical relationship $$${{{d^2}x} \over {d{t^2}}} + 6{{dx} \over {dt}} + 5x = 12\left( {1 - {e^{ - 2t}}} \right)$$$ The response o...
Choose two appropriate auxiliary components of a HVDC transmission system from the following $$1.$$ D.C. line inductor $$2.$$ A.C. line inductor $$3.$$ Reactive power sources $$4.$...
A surge of 20 kV magnitude travels along a lossless cable towards its junction with two identical lossless overhead transmission lines. The inductance and the capacitance of the ca...
The following program is written for an $$8085$$ microprocessor to add two bytes located at memory addresses $$1FFE$$ and $$1FFF$$ $$\eqalign{ & LXI\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,...
A power system consists of $$300$$ buses out of which $$20$$ buses are generator buses, $$25$$ buses are the ones with reactive power support and $$15$$ buses are the ones with fix...
Two conductors are carrying forward and return current of $$ + {\rm I}$$ and $$ - {\rm I}$$ as shown in Fig. The magnetic field intensity $$\overrightarrow H $$ at point $$P$$ is
A generator delivers power of 1.0 p.u. to an infinite bus through a purely reactive network. The maximum power that could be delivered by the generator is 2.0 p.u. A three-phase fa...
The voltage-flux adjustment of a certain $$1$$-phase $$220$$ $$V$$ induction watt-hour meter is altered so that the phase angle between the applied voltage and the flux due to it $...
The items in List $$-$$ $${\rm I}$$ represent the various types of measurements to be made with a reasonable accuracy using a suitable bridge. The items in List $$-$$ $${\rm II}$$...
The effect of stray magnetic fields on the actuating torque of a portable instrument is maximum when the operating field of the instrument and the stray fields are
A Manganin swamping resistance is connected in series with a moving coil ammeter consisting of a milli-ammeter and a suitable shunt in order to
A wattmeter reads $$400$$ $$W$$ when its current coil is connected in the $$R$$ phase and its pressure coil is connected between this phase and the neutral of a symmetrical $$3$$-p...
The inductance of a certain moving-iron ammeter is expressed as $$L = 10 + 3\theta - {{{\theta ^2}} \over 4}\mu H,\,\,$$ where $$\,\,\theta \,\,\,$$ is the deflection in radians fr...
A $$500$$ $$A/5$$ $$A,$$ $$50$$ $$Hz$$ current transformer has a bar primary. The secondary burden is a pure resistance of $$1\,\Omega $$ and it draws a current of $$5A$$. If the m...