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APTRANSCO AE Books |

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Re: APTRANSCO AE Books
As you want here I am suggesting name of book for Transmission Corporation of Andhra Pradesh (APTRANSCO) AE exam preparation: Electrical Power Systems ---- CL Wadhwa ( Back side Bits) Electrical Objectives ---- J.B.Gupta Electrical Machinery ----- PS Bimbra ( Networks + Machines) Backside bits Sample Question paper ::-- which of the following statements associated with purely resistive circuits is correct? (a) PF is unity (b) Power consumed is zero (c) Heat produced is zero (d) PF is zero The magnetic field energy in an inductor changes from maximum value to minimum value in in 5m sec when connected to an ac source. The frequency of the source is (a) 20 Hz (b) 50 Hz (c) 200 Hz (d) 500 Hz The transfer function of a system is used to determine a. the output for a given input b. the type of system c. the input for a given output d. the steady state gain In a servo system the voltage induced in the control transformer rotor is the a. error voltage b. driving voltage c. opposing voltage d. none of these With the feedback system, the transient response o decays slowly b. decays rapidly c. rises slowly d. rises quickly Voltage variable resister is? ans: FET Fault at generating station is? ans:L-G fault Transfer function of Tachometer is? ans: Ks The system whose characteristic equation has the following roots is marginally stable (a) -j, j, -1,1 (b) -3,-2,0 (c) -2+3j, -2-3j, -2 (d) -3,-2,-1 Electronic control systems have the serious draw-backs of (a) low reliability (b) operational difficulty (c) temperature sensitiveness (d) all of above The Direction of current in an ac circuit (a) is from positive to negative (b) is always in one direction (c) varies from instant to instant (d)Cannot be determined The ratio of voltage and electric current in a closed circuit (a) remains constant (b) varies (c) increases (d) falls The resistance of a wire varies inversely as (a) area of cross section (b) length (c) resistivity (d) temperature The electrical conductivity of metals is typically of the order of ( in ohm-1 m-1) (a) 10 to the power of 7 (b) 10 to the power of 5 (c) 10 to the power of -4 (d) 10 to the power of -6 A phase log compensation will (a) improve relative stability (b)increase the speed of response (c)increase band-width (d) increase overshoot For Nyquist plot we use a. open loop function b. closed loop function c. characteristic equation d. any of the above A system with gain margin close to unity or a phase margin close to zero is a. highly stable b. oscillatory c. relatively stable d. none of these Root locus diagram exhibits the a. frequency response of a system b. poles of the transfer function for a set of parameter values c. bandwidth of system d. all of the above Increase in the gain K makes the system a. more stable b. unstable c. none of above Which of the following types of instrument is an integrating instrument? a. power factor meter b. energy meter c. wattmeter d. frequent meter If the Supply voltage is increased by n times, the cross section of conducter will [increase/decrease] by ________ times ? The Frequency is measured by _________ bridge ? Which of the material is used for the ’swamping’ resistance that is connected in series with the working coil of a voltmeter? a. Constantan b. Manganin c. Eureka d. Nichrome The elements which are not capable of delivering energy by its own are known as (a) unilateral elements (b) non-linear elements (c) passive elements (d) active elements The magentic susceptibility of paramagnetic material is (a) less than zero (b) less than one but positive (c) greater than one (d) equal to zero What are used to increase the range of ammeters. a. Multipliers b. Shunts c. Control Springs d. Potential transformers Which voltmeter do you select for measuring 50KV DC? a. Moving Coil Voltmeter b. Hot wire voltmeter c. Electro Dynamo meter d. Electrostatic Voltmeter Which of the following you will prefer to extend the range of an ac voltmeter? a. Low series resistance b. high resistance in parallel c. CT d. PT Creeping is the phenomena occurs in a. voltmeter b. wattmeter c. energy meter d. ammeter The Source internal resitanse Rs , When equal to Load resistance RL, the maximum transfered is of _____ % of input power? solar cell is used like as a ………………….(photo voltaiac) frequency of RC-phase shift oscillator usig JFET is: zero-sequence nw of star(with solidneutral)-delta? given all the losses of IM then u have to find out efficiency? also given i/p sol: formula: (1-(losses/input))*100 in half adder sum is given by? ans:A EX-OR B in J-K FF race around condition occurs only when? ans:J=1,K=1 Four resistors, each of resistance R ohms are available. The minimum resistance of the combination will be (a) 4R (b) R (c) R/4 (d) R/8 for data trancemission which FF is used? ans-FF steady state stability can be det by? ans:final value thearom stability factor for self biased ckt is? slack bus is called as generator bus,loadbus,y bus ,zbus) water hammer effect produce inpenstock, surgetank the sag form b/w 2 poles is? ans:caternory active transduser is? anshoto voltaic cell Slack bus is reprasented as? ans:1.Zbus 2.ybus r/r’=.7788 To draw equal area criterion how many machines are used? ans: one machine at infinite bus. some problems are given based on the following formulas (1).surge impedence (2).Deq=(Dab Dbc Dca)^1/3 (3).Z p.u =(Kv)^2/(MVA) (4).Load Factor (5).Inductance L =GMD/GMR Problems based on the formula weather the given system K/((s+a)(s+b)) is ans:a. overdamped b. undamped c.stable write the formula for alpha in terms of beta? qn on characteristic impedance ans.characteristic impedance is independent on length High AC voltages are usually measured with a. magnetic voltmeter b. inductive voltmeter c. potential transformers with voltmeters d. current transformers and voltmeters
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