GATE 2000 Electrical Engineering
53 questions across 1 session
Feedback control systems are
The type of power amplifier which exhibits crossover distortion in its output is
A linear time-invariant system initially at rest, when subjected to a unit-step input, gives a response $$y\left( t \right) = t{e^{ - t}},\,\,t > 0.$$ The transfer function of the...
A dual-slope analog-to-digital converter uses an $$N$$-bit counter. When the input signal $${V_a}$$ is being integrated, the counter is allowed to count up to a value:
Which one of the following is not a vected interrupt?
An electron with velocity $$'u'$$ is placed in an electric field, $$E$$ and magnetic field, $$B.$$ The force experienced by the electron is given by
A unity feedback system has open-loop transfer function $$G\left( s \right) = {{25} \over {s\left( {s + 6} \right)}}.$$ The peak overshoot in the step-input response of the system...
A 1.8° step, 4-phase stepper motor has a total of 40 teeth on 8 poles of stator. The number of rotor teeth for this motor will be
The compensating winding in a dc machine
Ratio of the rotor reactance X to the rotor resistance R for a two-phase servomotor
A 240 V dc series motor takes 40A when giving its rated output at 1500 rpm. Its resistance is 0.3 ohms. The value of resistance which must be added to obtain rated torque at 1000 r...
A permanent magnet dc commutator motor has a no load speed of 6000 rpm when connected to a 120V dc supply. The armature resistance is 2.5 ohms and other losses may be neglected. Th...
In a constant voltage transformer (CVT), the output voltage remains constant due to
If an ac voltage wave is corrupted with an arbitrary number of harmonics, then the overall voltage waveform differs from its fundamental frequency component in terms of
A 3-phase delta/star transformer is supplied at 6000 V on the delta-connected side. The terminal voltage on the secondary side when supplying full load as 0.8 lagging power-factor...
A 3-phase, 4-pole squirrel cage induction motor has 36 stator and 28 rotor slots. The number of phases in the rotor is:
The power input to a 415 V, 50 Hz, 6 pole, 3-phase induction motor running at 975 rpm is 40 kW. The stator losses are 1kW and friction and windage losses total 2 kW. The efficiency...
A three phase, wound rotor induction motor is to be operated with slip energy recovery in the constant torque mode, when it delivers an output power P 0 at slop 's'. then theoretic...
The phase sequence of a three-phase alternator will reverse if
A single-phase, 2000 V alternator has armature resistance and reactance of 0.8 ohms and 4.94 ohms respectively. The voltage regulation of the alternator at 100 A load at 0.8 leadin...
A $$dc$$ motor with armature resistance $${R_a}$$ is fed from a step down chopper in the continuous mode, and operates at some known speed and known excitation current. The motor c...
In a thermal power plant, the feed water coming to the economiser is heated using
The corona loss on a particular system at 50 Hz is 1 kW/km per phase. The corona loss at 60 Hz would be
A thyristorised three phase fully controlled converter feeds a $$dc$$ load that draws a constant current. Then the input $$ac$$ line current to the converter has
The incremental cost characteristic of two generators delivering $$200$$ $$MW$$ are as follows $$\,\,\,{{d{F_1}} \over {d{P_1}}} = 20 + 0.1{P_1},\,\,{{d{F_2}} \over {d{P_2}}} = 16...
A unity feedback system has open loop transfer function $$G(s).$$ The steady-state error is zero for
A $$275$$ $$kV,$$ $$3$$-phase, $$50$$ $$Hz,$$ $$400$$ $$km$$ lossless line has following parameters: $$x=0.05$$ $$ohms/km,$$ line charging susceptance $$y=3.0$$ micro-Siemens/k. (a...
Open-loop transfer function of a unity - feedback system is $$$G\left( s \right) = {G_1}\left( s \right).{e^{ - s{\tau _D}}} = {{{e^{ - s{\tau _D}}}} \over {s\left( {s + 1} \right)...
Triangular $$PWM$$ control, when applied to a $$BJT$$ based three phase voltage source inverter, introduces.
A unity feedback system has open loop transfer function $$G\left( s \right) = {{K\left( {s + 5} \right)} \over {s\left( {s + 2} \right)}};K \ge 0$$ (a) Draw a rough sketch of the r...
The severity of line-to-ground and three phase faults at the terminals of an unloaded synchronous generator is to be same. If the terminal voltage is $$1.0$$ p.u. and $${Z_1} = {Z_...
In a 3-step distance protection, the reach of the three zones of the relay at the beginning of the first line typically extends upto
Show via the construction of a suitable Gaussian surface, that the capacitance of a spherical capacitor consisting of two concentric shells of radii $$a$$ and $$b$$ is given by $$C...
$$D\left( s \right) = {{\left( {0.5s + 1} \right)} \over {\left( {0.05s + 1} \right)}}$$ Maximum phase lead of the compensator is
A voltage wafeform $$v\left( t \right) = 12\,{t^2}$$ is applied across a $$1$$ $$H$$ inductor for $$t \ge 0,$$ with initial current through it being zero. The current through the i...
In an inverse definite minimum time, electromagnetic type over-current relay, the minimum time feature is achieved because of
A synchronous generator, having a reactance of 0.15 p.u., is connected to an infinite bus through two identical parallel transmission lines having reactance of 0.3 p.u. each. In st...
A two-port device is defined by the following pair of equations: $${i_1} = 2{v_1} + {v_2}$$ and $${i_2} = {v_1} + {v_2}$$ Its impedance parameters $$\left( {{z_{11}},\,\,{z_{12}},\...
The plug setting of a negative sequence relay is $$0.2$$ $$A.$$ The current transformer ratio is $$5:1$$. The minimum value of line to line fault current for the operation of the r...
Out of the considerations (i) to (iv) listed below, (i) No distance limitation related to steady state stability (ii) No reactive power requirement from the system at the two termi...
A three phase voltage source inverter supplies a purely inductive three phase load. Upon Fourier analysis, the output voltage waveform is found to have an $${h^{th}}$$ order harmon...
A $$2300$$ $$V,$$ $$3$$-phase synchronous motor driving a pump is provided with a line ammeter and a field rheostat. When the rheostat is adjusted such that the $$ac$$ line current...
An active filter consisting of an op-amp, resistor $${R_1},\,\,{R_2},\,\,{R_3}$$ and two capacitors of value $$C$$ each, has a transfer function $$T\left( s \right) = {{{{ - s} \ov...
A single phase voltage source of magnitude $${V_s}$$ and frequency $$\omega \,\,\left( {rad\,/\,\sec } \right)$$ is connected to an inductance $$L$$ through an antiparallel back-to...
An analog electronic circuit that measures $$rms$$ value of the input voltage by averaging the square of the instantaneous voltage level, responds slowly to changes in the input si...
A transmission line has equal voltages at the two ends, maintained constant by two sources. A third source is to be provided to maintain constant voltage (equal to end voltages) at...
A step down chopper operates from a $$dc$$ voltage source $${V_s}$$ feeds a $$dc$$ motor armature with a back $$e.m.f$$ $$\,\,{E_b}.$$ From oscilloscope traces, it is found that th...
A current amplifier has an input resistance of $$10\Omega ,$$ an output resistance of $$10\,\,k\Omega $$ and a Current gain of $$1000.$$ It is feed by a current source having a sou...
If an $$ac$$ voltage wave is corrupted with an arbitrary number of harmonics, then the overall voltage waveform differs from its fundamental frequency component in terms of
Consider the state equation $$\mathop X\limits^ \bullet \left( t \right) = Ax\left( t \right)$$ Given : $${e^{AT}} = \left[ {\matrix{ {{e^{ - t}} + t{e^{ - t}}} & {t{e^{ - t}}} \cr...
The two wattmeter method is used to measure active power on a three phase, three wire system. If the phase voltage is unbalanced, then the power reading is
Instrument transformers are known to introduce magnitude and phase errors in measurements. These are primarily due to
A $$3$$ - $$\phi $$ load operates with balanced voltages applied to its terminals, and draws balanced currents. The potential coil of a moving coil wattmeter is connected from $$R$...