Get here **TS TRANSCO AE Answer Key**. The Transmission Corporation of Telangana Limited successfully conducted the Assistant Engineer Exam for 206 posts. A lot of candidates appeared in this exam. TRANSCO exam held on 29 November 2015 at Hyderabad and Secunderabad. TS TRANSCO recruitment for 206 vacancies for the post of Assistant engineer in the department of electrical and civil. Candidate will be eager to know their Answer. Official TS TRANSCO Answer Key will be released soon on Official website. **transco.telangana.gov.in**

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## TS TRANSCO AE 29 November 2015 Answer key:

**Organization Name:** Transmission Corporation of Telangana Limited

**Post Name:** Assistant Engineering (AE)

**Total Vacancies:** 206

: Civil Post- 22

: Electrical Post-184

**Exam Date:** 29th November 2015

**Official Website:** www.transco.telangana.gov.in

**Sections A: Electrical Engineering**

- Millman’s theorem yields equivalent

(a) Impedance or Resistance

(b) Current source

(c) Voltage source

(d)**Voltage or Current source** - For the network shown in Fig. 1, when I=0, V=20 V and when R=0, I=10A. If now R=3W what is the value of the current I?

(a) 6.67A

(b) 6.0A

(c)**4.0A**

(d) 10.0A - In a pure resistive circuit, the average power P
_{avg}is ____ the peak power P_{max}.

(a) Double

(b)**One-half of**

(c) One-fourth

(d) Equal to - When the power transferred to the load in maximum, the efficiency of the power transfer is

(a) 25%

(b) 75%

(c)**50%**

(d) 100% - The source impedance Z
_{s}=(6+j8) W in the circuit shown (Fig. 2). Maximum real power is transferred to the load impedance when Z_{L}is equal to(a) (6+j8) W

(b) 6W

(c) 10 W

(d)**(6-j 8) W** - 3 shows two coils with coupling coefficient of 0.6, L
_{1}=0.4H and L_{2}=2.5H. The mutes inductance M is equal to

(a)**0.6 H**

(b) 2.9 H

(c) 2.1 H

(d) 1.45 H - In dc machines, the armature windings are placed on the rotor because of the necessity for

(a) electromechanical energy conversion

(b) generation of voltage

(c)**commutation**

(d) development of torque - The fall in speed of a dc generator due to increase in load can be corrected by

(a) cooling the armature

(b) increasing the excitation

(c) reducing the load voltage

(d)**increasing the input to the prime mover.** - Two transformers, each having iron loss of P
_{i}watts full load copper loss of P_{c}, are put to back to back test and full-load current is allowed to flow through the secondaries, the total input power will be

(a) 2 P_{i}

(b) 2 P_{c}

(c) P_{i}+ P_{c}

(d)**2(P**_{i}+P_{c}) - The desirable properties of transformer core material are

(a) low permeability and low hysteresis loss.

(b) high permeability and high hysteresis loss

(c)**high permeability and low hysteresis loss**

(d) low permeability and hysteresis loss - In a synchronous machine, if the field flux axis ahead of the armature field axis in the direction or rotation, the machine is operating as

(a) synchronous motor

(b)**synchronous generator**

(c) asynchronous motor

(d) asynchronous generator - In an induction motor if the flux density is reduced to one-half of it normal value then the torque will

(a) reduce to one-half

(b)**reduce to one-fourth**

(c) remain unchanged

(d) increase four times - How can the steady-state error in a system be reduced?

(a) By decreasing the type of system

(b) By increasing system gain

(c)**By decreasing the static error constant**

(d) By increasing the input - The purpose of guard ring in transmission lines is to

(a)**reduce the earth capacitance of the lowest unit**

(b) increase the earth capacitance of the lowest unit

(c) reduce the transmission lines losses

(d) reduce the reactance of the line - Load flow studies involves solving simultaneous

(a) linear algebraic equation

(b)**non-linear algebraic equations**

(c) linear differential equations

(d) non-linear differential equations. - Which portion of the power system is least prone to fault?

(a) alternators

(b)**switchgear**

(c) transformers

(d) overhead lines - In the solution of load-flow equation, Newton-Raphson (NR) method is superior to the Gauss-Seidal (GS) method, because

(a) the time taken to perform one iteration in the NR method is less when compared ot the time taken int eh GS method

(b) number of iteration required is not independent of the size of the system in the NR method.

(c) number of iteration required in the NR method is more when compared to that in the GS method

(d) convergence characteristics of the NR method are not affected by the selection of slack bus. - A voltage source inverter will have better performance if its.

(a) load inductance is small and source inductance is large

(b) both load and source inductance are small

(c) both load and source inductances are large(d)

**load inductance is large and source inductance is small** - A 3-phase wound rotor induction motor is controlled by a chopper-controlled resistance in its rotor circuit. A resistance of 2W is connected in the rotor circuit and a resistance of 4W is additionally connected during OFF periods of the chopper. The OFF period of the chopper is 4ms. The average resistance in the rotor circuit for the chopper frequency of 200 Hz is

(a) 26/5 W

(b)**24/5W**

(c) 18/5W

(d) 16/5W - The main function of economizer of a boiler plant is to

(a) increase steam production

(b) reduce fuel consumption

(c) increase stem pressure

(d)**increase**life**of the boiler** - A dc chopper is fed from a constant voltage mains the duty ratio of chopper is progressively increased while the chopper feeds and RI load. The per unit current ripple would

(a) increase progressively

(b) decrease progressively

(c) decrease to a minimum value at a=0.5 and then increase

(d)**increase to a maximum value at a=0.5 and then decrease** - The Boolean expression Y (A, B, C)=A+BC is to be reliazed using 2-input gates of only one type. What is the minimum number of gates required for realization?

(a) 1

(b) 2

(c)**3**

(d) 4 or more - The output of the 4-to-I MUX shown in the Fig. 4 is

(a) xy+x

(b)**x+y**

(c) x + y

(d) xy +x - For an n-channel MOSFET and its transfer curve shown in the Fig. 5, the threshold voltage is

(a)**1 V and the device is in active regions**

(b) -1 V and the device is in saturation region

(c) 1 V and the device is in saturation region

(d) -1 V and the device is in active region - The Common Mode Rejection Ratio (CMRR) of a differential amplifier (where A
_{d}=differential gain, A_{C}= common mode gain)

(a)**A**_{d}/A_{c}

(b) (A_{d}-A_{c})/A_{d}

(c) 20 log_{10}(A_{d}/A_{c})

(d) 20 log_{10}(A_{c}/A_{d}) - What is the Gray code word for the binary number 101011?

(a)**101011**

(b) 110101

(c) 011111

(d) 111110 - Ideally, the damping torque should be

(a)**Proportional to**velocity**of the moving system and operating current.**

(b) Proportional to the velocity of the moving system but independent of operating current.

(c) Independent of the velocity of the moving system and proportional to the operating current

(d) Independent of the velocity of the moving system and operating current. - An ac voltmeter using full-wave rectification and having a sinusoidal input has an ac sensitivity equal to

(a) 1.414 times dc sensitivity

(b) dc sensitivity

(c)**0.9 times dc sensitivity**

(d) 0.707 times dc sensitivity - An electrodynamometer type wattmeter is connected (as shown in the given Fig. 6) in a 3-phase supply and having a 3-phase balanced load, E and I are the value of phase voltage and current and f is the phase angle between them. The wattmeter reading will be

(a)**proportional to EI sin f**

(b) proportional to EI cos f

(c) proportional to EI tan f

(d) zero - Three-pulse converter has a freewheeling diode across its load. The operating range of the converter is

(a)**0**^{o }£ a£ 150^{o}

(b) 60^{o}£ a£ 120^{o}

(c) 30^{o}£ a£ 150^{o}

(d) 180^{o}£ a£ 360^{o} - The material used in liquid fuses is

(a) SF_{6}

(b) distilled water

(c)**carbon tetra chloride**

(d) transformer oil - The arc voltage in a circuit breaker is

(a)**in the phase with the arc current**

(b) lagging the arc current by 90^{o}

(c) leading the arc current by 90^{o}

(d) lagging the arc current by 180^{o} - Buchholz relay is

(a) located in the conservator tank

(b) located in the transformer tank itself

(c)**connected in the pipe connecting**main**tank of transformer and conservator**

(d) installed in the circuit breaker - For protection of rotating machines against lighting surge ____ is used.

(a) lightning arrester

(b) capacitor

(c)**combination of lightning arrester and capacitor**

(d) lighting conductor and arrester - The inrush current of a transformer at not load is maximum if the supply voltage is switched on

(a) at peak voltage value

(b)**at zero voltage value**

(c) at half voltage value

(d) at0.866 time voltage value - The positive, negative and zero-sequence impedances of a solidly grounded system under steady-state condition always follow the relations

(a) Z_{0}<Z_{1}<Z_{2}

(b)**Z**_{1}>Z_{2}>Z_{3}

(c) Z_{1}<Z_{2}<Z_{3}

(d) Z_{0}>Z_{1}>Z_{2} - The stability of the power system is not affected by

(a) generator reactance

(b) line reactance

(c) line losses

(d)**output torque** - The ‘Equal are criterion’ for the determination of transient stability of a synchronous machine connected to an infinite bus

(a)**ignores line as well as synchronous machine resistance and shunt capacitances.**

(b) assumes accelerating power acting on the rotor as constant.

(c) ignores the effect of voltage regulator and governor but considers the inherent damping present in the machine.

(d) takes into consideration the possibility of machine losing synchronism after it has survived during the first swing. - Reflector mirrors employed for exploiting solar energy are called the

(a) Mantle

(b)**Heliostats**

(c) Diffusers

(d) Ponds - The capital cost of a power plant depends on

(a) Total installed capacity only

(b) Total number of units only.

(c)**Total installed capacity and number of units as well**

(d) Neither the installed capacity nor number of units - The load duration curve for unity load factor will be of

(a)**rectangular shape**

(b) Triangular shape

(c) L-shape

(d) I-shape - The knowledge of diversity factor helps in computing

(a) Plant capacity

(b) Average load

(c) Units (k Wh) generated

(d)**Peak demand** - In parallel RLC resonance circuit at resonance the current will be

(a)**Minimum**

(b) Maximum

(c) Zero

(d) Infinite - A transformer has negative voltage regulating when its load power factor is

(a) Zero

(b) Unity

(c)**Leading**

(d) Lagging - Load factor is the

(a) Ratio of maximum load on the station to sum of consumer’s maximum load.

(b)**Ratio of average demand to maximum demand.**

(c) Factor used for increasing load

(d) Reciprocal of (1). - The skin effect in conductors is due to non-uniform distribution of current in it and major portion of current is near the _____ of conductor.

(a)**Surface**

(b) Center

(c) Complete cross sections area

(d) Axis - In lead acid battery the density of acid indicates the

(a) charge of the battery

(b)**level of acid**

(c) e.m.f. of the battery

(d) damage of the plates - Breaking capacity of a circuit breaker is usually expressed in terms of

(a) Ampere

(b) Voltas

(c) MW

(d)**MVA** - _____ is used for heating non-conduction materials.

(a) Eddy current heating

(b) Arc heating

(c) Induction heating

(d)**Dielectric heating** - Spot welding is used for

(a)**Thin metal**

(b) Rough and irregular surface

(c) Casting only

(d) Thick sections - For arc welding current range is usually

(a) 10 to 15 A

(b) 30 to 40 A

(c) 50 to 100 A

(d)**100 to 350 A** - According to the Routh Hurwithz stability criterion for a stable system, which of the following statement is correct?

(a) Roots are in rights half of the S-plane

(b)**Roots are in the left half of the S-plane**

(c) Roots are in right half of the S-plane on imaginary axis

(d) Roots are in the left half of S plane on imaginary axis - If the gain of the open loop system is doubled, the gain margin

(a) Is not affected

(b) Gets doubled

(c)**Becomes half**

(d) Becomes one-fourth - Phase margin is the amount of angle to make the system

(a)**Oscillatory**

(b) Stable

(c) Unstable

(d) Exponential - The voltage gain of a common source JFET amplifier depends up on its

(a) Input impedance

(b) Amplification factor

(c)**Dynamic drain resistance**

(d) Drain load resistance - A four-quadrant operation requires two full converters connected in

(a) Series

(b) Parallel

(c)**Back to Back**

(d) Series Cascade - Oscillator independent of phase shift is

(a) Relaxation

(b) Wein bridge

(c) Clapp

(d)**All of these** - In a dual converter the circulating current

(a) allow smooth reversal of load current but increase the response time

(b) does not allow smooth reversal of load current. But reduces the response time

(c)**allows smooth reversal of load current with improved speed of response**

(d) flows only if there is not interconnecting inductor. - A digital voltmeter has 4½ digital display the 1 V range can read upto

(a) 1000

(b) 1.111

(c)**1.999**

(d) 1999 - For a short transmission line with r/x ratio of is 1.0. the regulation will be zero when the load power factor is

(a) Unity

(b)**0.707 lead**

(c) 0.707 lag

(d) Zero power factor lead - A battery consists of n series connected cells while voltage of each cell is v volts and capacity k. The voltage and capacity of battery is

(a)**Voltage of battery =n*v, Capacity of batter=Capacity of each cell**

(b) Voltage of battery=n*v, Capacity of battery=n*Capacity of each cell

(c) Voltage of battery=v, Capacity of battery= n*Capacity of each cell

(d) Voltage of battery =v, Capacity of battery =Capacity of each cell - Torque ‘d’ is the angel between

(a) Rotor field axis and resultant field axis

(b)**Stator field axis and rotor field axis**

(c) Stator field axis and mutual field axis

(d) Stator field axis and resultant field axis - Steady state power limit is

(a)**EV/X**

(b) EV/X sind

(c) EV/X cos d

(d) EV/X sin 30^{o} - Undamped frequency of oscillations of a synchronous machine is

(a)**(P**_{g}^{/}/M)^{5}

(b) (P_{g}^{/}/M)^{2 }(c) (P_{g}^{/}/M)^{4}

(d) (P_{g}^{/}/M)^{2} - The first two rows of Routh’s tabulation of a fourth order system are

S^{4}1 1 0 5

s^{3}2 20

The number of roots of the system lying on the right half of s-plane is

(a) 0

(b)**2**

(c) 3

(d) 4 - A negative sequence relay is used for protection of

(a)**Generator**

(b) Transformer

(c) Motor

(d) Long Transmission lines - The surge impedance for over head line is taken as

(a) 10-20 ohms

(b) 50-60 lhms

(c)**100-200 ohms**

(d) 1000-2000 ohms - In an ac series RLC circuit the voltage across R and L is 20 V; voltage across L and C is 9 V and voltage across RLC is 15V. What is the voltage across C?

(a)**7V**

(b) 12 V

(c) 16 V

(d) 21 V - The motor used for electric traction is

(a) D.C. shunt motor

(b) D.C. compound motor

(c)**D.C. series motor**

(d) Synchronous motor - Arc resistance

(a) increase with increase in arc current

(b)**decrease with increase is arc current**

(c) is independent of arc current

(d) is independent of arc length - An unity feedback control system has open-loop transfer function G(s)=9/[s(s+1)]. The damping ratio x of the system is

(a)**1.0**

(b) 0.3

(c) 0.6

(d) 0.5 - Power in the wind is proportional to

(a) Wind velocity

(b) (Wind velocity)^{2}

(c)**(Wind velocity)**^{3}

(d) (Wind velocity/2) - In order to regulate steady state error to zero, in a negative feedback control system, one employs

(a) Proportional control

(b)**Integral control**

(c) Derivative control

(d) Proportional-Derivation control - For a PV cell, V
_{oc}=open circuit voltage; I_{sc}= short circuit current; V=load voltage and I=load current. At Maximum Power Point (MPP) for this PV cell

(a) V<V_{oc}and I=I_{sc}

(b) V<V_{oc}and I< I_{sc}

(c) V=V_{oc}and I=I_{sc}

(d) V=V_{oc}and I<I_{sc} - The closed loop transfer function of a control system

C (s) R(s) I (I-s)

The steady state value of output value of output c(¥) for unit step input is equal to

(a)**1.0**

(b) 0.5

(c) zero

(d) 2 - Fig. 7 shows an accurate equivalent circuit for a PV cell. For this cell

(a) R_{p}=R_{s}

(b) R_{p}<R_{s}

(c) R_{p}>R_{s}

(d) Product of R_{p}and R_{s}is unity - The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque

(a) Decreases

(b)**Increases**

(c) Remains constant

(d) None of the above - An amplifier has a voltage gain of 120. To reduce distortion, 10% negative feedback is employed. The gain of the amplifier with feedback is

(a) 141

(b) 92.3

(c)**9.23**

(d) 1.41 - The time base signal in Cathode Ray Oscilloscope (CRO) is

(a) A square wave signal

(b)**A sawtooth signal**

(c) A triangular wave signal

(d) A sinusoidal signal - A control system having unit damping factor will give

(a) Oscillatory response

(b) Undamped response

(c)**Critically damped responses**

(d) No response

**Section B: General Awareness and Numerical Ability**

- It looks _______ it’s going to rain.

(a) as

(b)**as if**

(c) although

(d) supposing - Which sentence is right?

(a) Unless you work hard. You will win.

(b) As it was too hot, so I switched the air cooler on

(c)**Owing to his goods nature, he was liked by all**

(d) It was too dirty for holding it with hands. - Most students have to try and earn money by taking a holiday job. They turn ____ their studies and experience the real world for a while

(a) into

(b) down

(c)**aside from**

(d) to - In ______ nothing much happened at the meeting.

(a) quick

(b) briefly

(c)**short**

(d) shortly - Railway Minister ______ visited Japan?

(a) Arun Jaitley

(b)**Suresh Prabhu**

(c) Amriti Irani

(d) Manohar Parrikar - Former President of the Board of Control for Cricket in India (BBCI), _____ passed away very recently?

(a) Alok Rawat

(b) Upendra Tripathy

(c) S.M. Vijayanand

(d)**Jagmohan Dalmiya** - PM Narendra Modi inaugurated first branch of ______ in China at Shanghai during his official visit to China?

(a) SBI

(b) Axis Bank

(c) HDFC Bank

(d)**ICICI Bank** - ISRO launched ____ Multi Wavelength Space Observatory along with six foreign customer satellites through PSLV-30 Lauched Vehicle?

(a) GAGAN

(b) AGNI

(c)**ASTTOSAT**

(d) GSLV - Which Kakatiya ruler laid the foundation for the Warangal fort.

(a) Prola-1

(b) Prola-2

(c) Beta-1

(d) Rudramadevi - The famous shia festival of Qutub Shahai age in Telangana was

(a)**Muharram**

(b) Ramzan

(c) Nauroj

(d) Bakrid - Identify the birth place of ‘Komaram Bheem’.

(a)**Jodeghat**

(b) Nirmal

(c) Asifabad

(d) Khanajipet - The famous ‘Telangana March’ was held on

(a) 3^{rd}September, 2012

(b) 28^{th}September 2012

(c) 29^{th}September, 2012

(d)**30**^{th}September, 2012 - In 10 years, A will be twice as old as B was 10 years ago. If A is now 9 years older than B, the present age of B is

(a) 19 years

(b) 29 years

(c)**39 years**

(d) 49 years - If each side of a square is increased by 25%, then the percentage change in its area is

(a) 35.25%

(b) 42.35%

(c)**56.25%**

(d) 63.45% - A trader mixes three varieties of groundnuts costing Rs. 50, Rs.20 and Rs.30 per kg in the ratio 2:4:3 in terms of weight, and sells the mixture at Rs.33 per kg. What percentage of profit does he make?

(a) 8%

(b) 9%

(c)**10%**

(d) 11% - A car complete a journey in 10 hours. He travels first half of the journey at the rate of 21 km/hr and second half at the rate of 24 km/hr. Find the total journey in km.

(a) 220 km

(b)**224 km**

(c) 230 km

(d) 234 km - Main memory is also called as

(a) ROM

(b) Hard Dish

(c)**RAM**

(d) PROM - Secondary storage device can perform

(a) Arithmetic operation

(b) Logic Operation

(c)**Fetch operation**

(d) None of these - The IC chips, used in computers, is made of

(a) Iron oxide

(b)**Silicon**

(c) Graphite

(d) silica - Which of the following programming languages are considered as low level language?

(a) Basic, Cobol, Fortran

(c) Assembly language

(b)**C, C++**

(d) Prolog