Thursday, August 28, 2014

UPSC IES -Nuclear Tech Solved Questions

Past IES Questions –Nuclear Tech (Solved)
With Detailed explanations and notes which I prepared for my exam. Keep reading, keep testing.

24. The energy produced by 4-5 tons of high grade coal is equivalent to the energy produced
by
(A) 1 kg of Uranium (B) 1 gram of Uranium
(C) 100 grams of Uranium (D) 10 grams of Uranium

Fact: A kilogram of uranium-235 (U-235) converted via nuclear processes releases approximately three million times more energy than a kilogram of coal burned conventionally (7.2 × 1013 joules per kilogram of uranium-235 versus 2.4 × 107 joules per kilogram of coal).[

25. Enriched Uranium is one in which
(A) Percentage of U235 has been artificially increased
(B) Percentage of U238 has been artificially increased
(C) Percentage of U234 has been artificially increased
(D) Extra energy is pumped from outside

26. Which one of the following statements is not correct ?
(A) Fusion is the combination of heavy nuclei of elements resulting in the release of heat energy
(B) Neutron bombardment is the most common and practiced method of initiation of reaction in fission materials
(C) When the multiplication factor is greater than 1, the chain reaction is uncontrollable
(D) The reactor produces , , and neutron radiations. Of all these radiation is the
most dangerous

27. The reflectivity in a reactor depends upon
(A) Geometry of the reflector (B) Energy of neutrons (C) Properties of reflector (D) All of these

28. Shielding in a nuclear power plant is done
(A) To protect against neutron and gamma rays
(B) To absorb excess neutrons
(C) To slow down the speed of fast moving neutrons
(D) To return the neutrons back into the core of the reactor

Q Moderator in nuclear power plant is used to : slow down the fast moving neutrons

Q With natural Uranium : Heavy Water , solid Graphite & Beryllium are used as moderators

Q Radiations against which shielding is to be given are (in nuclear plant)  : neutron & gamma

Q Moderator : Beryllium & Heavy Water

Q Fertile : U233, Atomic No –No of protons, Mass defect: binding energy, scattering: new born fission neutron have energy varying between 0.075 to 17Mev. During travel, they collide with other nuclei and slow down. This is scattering.

Q Energy released during fission of U235 is 193 MEV (say 200Mev)

Q. Gas cooled reactor: CO2 as Coolant & Graphite as moderator  [ both enriched & natural uranium used]
For fast reactors : best coolants are liquid metals such as sodium. Added advantage they can be used unpressurized as their boiling pt at atm pressure are very high.

CANDU type reactors use Heavy water as moderator

Q Fissile material: Pu-239, Pu-241, U-233,235,239 etc
    Fertile : Th-232, U-234,238,Pu 238,Pu240, Cadmium : Poison
·       Poison Fact: In other reactors the coolant acts as a poison by absorbing neutrons in the same way that the control rods do. In these reactors power output can be increased by heating the coolant, which makes it a less dense poison. Poison; Boron in the form of boric acid
·       A neutron poison (also called a 'neutron absorber' or a 'nuclear poison') is a substance with a large neutron absorption cross-section in applications, such as nuclear reactors[1]. In such applications, absorbing neutrons is normally an undesirable effect. However neutron-absorbing materials, also called poisons, are intentionally inserted into some types of reactors in order to lower the high reactivity of their initial fresh fuel load..
·       The capture of neutrons by short half-life fission products is known as reactor poisoning; neutron capture by long-lived or stable fission products is called reactor slagging.
·       Light water reactors (BWR, PWR) and heavy water reactors (HWR) operate with "thermal" neutrons, whereas breeder reactors operate with "fast" neutrons.
·       Control Rods: Silver (80%) , Indium (15%) & Cadmium (5%) alloys.
·       Liquid Metal Fast Breeder Reactor (LMFBR)  :This is a reactor design that is cooled by liquid metal, totally unmoderated, and produces more fuel than it consumes. They are said to "breed" fuel, because they produce fissionable fuel during operation because of neutron capture.
·        Moderators: Water, Heavy water, Graphite, Beryllium, Lithium.
·       In a nuclear reactor, the neutron population at any instant is a function of the rate of neutron production (due to fission processes) and the rate of neutron losses (via non-fission absorption mechanisms and leakage from the system). When a reactor’s neutron population remains steady from one generation to the next (creating as many new neutrons as are lost), the fission chain reaction is self-sustaining and the reactor's condition is referred to as "critical". When the reactor’s neutron production exceeds losses, characterized by increasing power level, it is considered "supercritical", and; when losses dominate, it is considered "subcritical" and exhibits decreasing power.


Q  CANDU  type reactor using natural uranium finds extensive use because:
·       Heavy water used both as coolant and moderator
·       Cost of fuel is much lower than in pressurized water or boiling water reactor,
·       Small leakage of heavy water does not affect the performance of the reactor substantially,
·       Fuel consumption is low coz of use of heavy water.

Q U-233 –prepared fuel, U-235: primary fuel, graphite: moderator, control rod: cadmium

Q In gas cooled thermal reactor: CO2 used as coolant and Graphite used as moderator
Fast reactors using enriched uranium fuel donot require a moderator
In fast reactors, liquid sodium is used as coolant

Q Thermal efficiency of a nuclear power plant using boiling water reactor is higher than of a plant using pressurized water reactor

R: in former, steam is directly allowed to be generated in the reactor itself, in latter steam is generated in a separate boiler by heat exchanger device using water of primary circuit which absorbs the fission energy.


CANDU advantages:

§ The main advantage of heavy water moderator over light water is reduced absorption of the neutrons that sustain the chain reaction

§ The low 235U density in natural uranium also implies that less of the fuel will be consumed

§ CANDU most of the moderator is at lower temperatures than in other designs, reducing the spread of speeds and the overall speed of the moderator particles. This means most of the neutrons will end up at a lower energy and be more likely to cause fission, so CANDU not only "burns" natural uranium, but it does so more effectively as well.
§ Major advantage to the heavy water design; it not only requires less fuel, but as the fuel does not have to be enriched, it is much less expensive as well.
§ A further unique feature of heavy-water moderation is the greater stability of the chain reaction. This is due to the relatively low binding energy of the deuterium nucleus (2.2 MeV), leading to some energetic neutrons and especially gamma rays breaking the nuclei apart and producing extra neutrons
§ Quiz

1
Uranium has isotopes
(a) U234      (b) U235      (c) U238      (d) all of the above      (e) none of the above
2
Nuclear reactor are used
(a) to produce heat for thermoelectric power      (b) to produce fissionable materials
(c) to propel ships, submarines, aircrafts            (d) all of the above
(e) none of the above
3
Enriched uranium may contain fissionable contents from
(a) 1 to 40%         (b) 10 to 50%          (c) 1 to 80%          (d) 1 to 99%
4
Ordinary water is sometimes used as moderator when enriched uranium is used as a fuel in nuclear power plants
(a) Yes          (b) No
5
The reflectivity of a reflector is defined as the fraction of neutrons entering the reflector which are returned to the core
(a) Agree          (b) Disagree
6
If the fuel is rich in fissionable material, the reactor can be made more compact than if the percentage of fissionable atoms is small
(a) Agree           (b) Disagree
7
The material most commonly used for shielding is
(a) carbon     (b) lead     (c) concrete     (d) all of the above    (e) none of the above
8
The first nuclear power plant in India was located at
(a) Kota           (b) Tarapur           (c) Barelly
9
The energy released from uranium fission is about ....... million electron volts.
(a) 100            (b) 200                 (c) 300               (d) 400
10
The nuclear power station at Tarapur has the reactor of the ........Type.
(a) pressurized water             (b) boiling water
(c) gas cooled                       (d) liquid metal cooled
11
A fission chain reaction in uranium can be developed
(a) by increasing the contents of U235
(b) by slowing down fast neutrons so that U235 fission continues by slow neutron
(c) both (a) and (b)

(d) none of the above
12
The slowing down of fast neutrons is desirable because slow moving neutrons are more effective than fast neutrons in triggering fission
(a) Agree           (b) Disagree
13
Light weight substances can not be effective moderators
(a) True              (b) False
14
Reflector in nuclear power plants is used to reflect neutrons back into the active core
(a) True              (b) False
15
The reflectivity depends upon
(a) geometry of the reflector                   (b) energy of neutrons
(c) properties of the reflector                  (d) all of the above
16
A reactor capable of converting a fertile material into fissile isotopes is called regenerative reactor
(a) Yes             (b) No
17
A nuclear power plant differs from a conventional steam power station only in the generating part
(a) Agree           (b) Disagree
18
U233 is produced
(a) artificially                                                      (b) as basic raw material
(c) when thorium is irradiated by neutrons            (d) by fission of U238
19
Each fission of U235 produces on the average ..... fast neutrons as a product of reaction
(a) 2.46          (b) 24.6         (c) 246            (d) 2460
20
A moderator generally used in nuclear power plants is
(a) graphite      (b) heavy water  
    (c) concrete      (d) graphite and concrete
21
Where reactor operation is designed with fast neutrons such as in reactors using highly enriched fuel, the moderator used is
(a) heavy water                 (b) graphite
(c) carbon dioxide              (d) no moderator is needed
22
Materials which make good moderators do not make good reflectors

(a) Right                (b) Wrong
23
Solid fuel fabricated into various small shapes, which are assembled to form fuel elements, is in the form of
(a) plates               (b) pallets              (c) pins
(d) all of the above              (e) none of the above
24
The sensing element in the control system of nuclear reactors measure the ....... of the neutron flux in the reactor
(a) temperature      (b) volume      (c) density      (d) none of the above
25
The predominant isotope of the naturally occurring element is
(a) U235      (b) U238      (c) Pu233      (d) Pu239

UPSC Engineering Services- English Vocab Questions (GAT)

This is summary of Vocabulary asked in ESE in past decade which I prepared during my preparations. This may serve as a ready reckoner and a check list. Have fun...

2010
  • BEMOAN : To express grief, disapproval, deplore
  • PROSAIC : Lacking in imagination and spirit; dull
  • OMINOUS: portending evil
    or harm
    ; foreboding; threatening; inauspicious
  • ELOQUENT : Characterized by persuasive, powerful discourse
  • FRAIL : fragile, weak
  • DERELECT : 1. Run-down; dilapidated  2. Neglectful of duty or obligation; remiss
  • INJUNCTION : a command,
    directive, or order  (legal)
  • IMPLORE : To beg for urgently; entreat, beseech
  • GROTESQUE : ludicrous or incongruous distortion ; Outlandish or bizarre
  • PERTINENT : having precise or logical relevance ; apt; germane (suitable, relevant & appropriate)
  • PAROCHIAL : religious; narrow-minded; provincial  ( a parochial outlook)
  • FICKLE  : liable to change; unstable, capricious (fickle minded) ; mercurial
  • DISGRUNTLED  : displeased and
    discontented
  • VIBRANT : vigorous, full of life
  • FORBIDDING : Unpleasant; disagreeable ; make approach or passage difficult (forbidding walls)
  • REPRIMAND : an act or expression of criticism and censure; To reprove severely; to reprehend
  • TENTATIVE
  • MARVELLOUS
  • RAMSHACKLE : in deplorable condition; derelict; dilapidated;
    tatterdemalion
    ; tumble-down
  • LUSH  : Abundant; plentiful
  • SINISTER : threatening or portending evil, harm, or trouble; ominous (sinister remark, smile, purpose)
  • ENTREAT : to plead with especially in order to persuade
  • REPROACH : To express disapproval of,
    criticism of, or disappointment in
(it means reproach or reviling; in the latter, blasphemy in the
usual sense of that term, denoting reproachful words concerning God)
Blasphemy : is irreverence toward holy personages, religious artifacts, customs

2009
·       ESCALATE
·       FLIPPANT : frivolously disrespectful, shallow, or lacking in seriousness; characterized by
levity
·       ALACRITY
·       BLEMISHES
·       INCESSANT
·       CRYPTIC
·       CLEMENCY : A merciful, kind, or lenient act
·       ABOMINABLE
·       RETRIBUTION : a justly deserved penalty, comeuppance
·       RESURRECTION : The act of rising from the dead or returning to life
·       SCOWL : To express with a frowning facial expression
·       EXONERATE
·                                                              ARRAIGN : (legal) Either way, at some point, before a case can formally begin, a person must be
arraigned. This simply means that the Defendant is brought before a Judge
·       IMPUDENCE : The quality of being
offensively bold
·       NAIVE
·       ABORTIVE
·       DAMNATION : The state of being damned; condemnation ( Salvation is opposite)
·       CARNAL : fleshly; sensual; given to sensual indulgence; lustful


2008
·       BEAVER AWAY : work hard on something
·       BADGER : pester, To tease or annoy
·       SWISH
·       SURREPTITIOUS
·       SURROGATE
·       UP THE CREEK : in deep trouble
·       CAVEAT
·       NIP AND TUCK : close in race, inconclusive
·       COMEUPPANCE : well deserved retribution, punishment
·       CELERITY : Swiftness of action or motion, legerity
·       SLOTH : Carelessness, disinclined at work
·       SALACIOUS : lecherous, Appealing to or stimulating sexual desire; lascivious
·       SEDULOUS : Diligent in application or pursuit
·       SWINGEING: very large, high, or severe <swingeing fines> <swingeing taxes>
      -Homeowners now face swingeing increases in their bills.
     -a swingeing criticism of the government's policies
·       TEDIUM:  the state of being bored
·       TENDENTIOUS : biased, having or marked by a
strong tendency especially a controversial one
                                     Where tempers flare
and a partisan/tendentious spirit provokes new hostility
·       TEMERITY : fearless, daring, audacious
·       CAPRICE : sudden, unpredictable or whimsical change; impulse  ( Capricious - impulsiveness)

      2007
·         GARISH : Marked by strident color or excessive ornamentation; gaudy
·         WRAITH : apparition, specter, ghost
·         TIMOROUS : Full of apprehensiveness; timid
·         EXPLICATE : explaining; explanation; exposition;
interpretation
·         EXACTION : Excessive or unjust demand; extortion
·         DANK : moist and wet
·         PORTENTIOUS : foreboding: 'The present
aspect of society is portentous of great change'
·         SURREPTITIOUS
·         CONSCIENTIOUS
·         CUT TO THE QUICK : to hurt deeply, usually in an emotional way;
·         FASTIDIOUS : extremely critical hard to please
·         GRATUITIOUS : grateful means feeling or showing gratitude or feeling thankful; gratified
means having received what was desired; gratuitous means costing nothing

When people refer to gratuitous violence or gratuitous sex they are usually criticizing violence or sex that didn't add anything to the plot but instead was just thrown in as a 'freebie.'

·         SEQUESTERED
·         MARTINET : strict disciplinarian
·         PARSIMONIOUS : miser
·         KNACKERED : exhausted
      She was too knackered to join them for dinner.
absolutely knackered, so no pub-crawling for me    tonight
·         CHARLATAN : person claiming more knowledge than he has
·         QUIXOTIC : extravagantly chivalrous or romantic; visionary, impractical,
·         IMPECUNIOUSNESS
·         FECKLESS : Careless and irresponsible
·         PROLIX : wordy ( Opposite is :Terse)
·         CRAVEN : Coward, Characterized by abject fear; cowardly; poltroon
      coward, craven, dastard, milksop, varlet, weakling, yellowbelly
·         INCHOATE : Incipient, Rudimentary, Inceptive(inception)
·         SUPERCILIOUS : Feeling or showing haughty disdain
·         TO PULL WOOL OVER EYES
·         CHAPERON: A person, especially an older or
married woman, who accompanies a young unmarried woman in public
·         RAMBUNCTIOUS : difficult to control or handle; wildly boisterous: a rambunctious child

2006
  • CAPRICE : sudden, unpredictable or whimsical change; impulse  ( Capricious - impulsiveness)
  • VESTIGE : visible trace, evidence, or sign of something that once existed but exists or
    appears no more
  • ADVENTITIOUS : Not inherent but added extrinsically; associated by chance and not an integral part
      accidental, fortuitous, contingent, incidental, adventitious
  • OBSTREPEROUS : Noisily and stubbornly defiant, marked by unruly or aggressive noisiness :
    clamorous
       she is not referring to the stress associated with the presence of recalcitrant
children and an obstreperous spouse
  • PUERILE
  • NIT-PACKING : Minute, trivial, unnecessary, and unjustified criticism or
    faultfinding
  • SPICK AND SPAN : Immaculately clean;
    spotless ( neat & clean)
  • DILETTANTE : admirer of the fine arts; dabbler; amateur;
    nonprofessional
  • UNBRIDLED
  • ERUDITE
  • APPROABATION : An expression of warm approval; praise
  • CONTUMACIOUS : is an obstinate disobedience of the lawful
    orders of a court
    .
  • STERILE
  • PRODIGIOUS
  • ASSIDUITY
  • CHOLERIC : Easily angered; bad-tempered
2005
·                                     HIATUS
·                                     HEARSAY : Unverified information; rumor; grapevine; scuttlebutt
·                                     DEFT : skillful agile, clever, adept, dexterous, adroit    (Opposite: Inept)  Adept-Inept
·                                     IMPLICATE
·                                     VENERATION : Reverence, (izzat dena )
·                                     THWART
·                                     TENUOUS : weak , thin
·                                     VEHEMENCE : zealous; ardent; impassioned: a vehement defense; vehement enthusiasm
·                                     VEXED
·                                     MIFFED
·                                     PREPOSSESSING : Serving to impress favorably; pleasing: a prepossessing
appearance
·                                     SLEUTHS : detectives
·                                     OPPROBRIUM : disgrace, a state of extreme dishonour.
·                                     ANNALS : a record of events arranged in yearly sequence
·                                     INSOLENT : Audaciously rude or disrespectful, Arrogance
·                                     PROCRASTINATION
·                                     COGITATE
·                                     CLEMENT : Inclined to be lenient or merciful

2004
·       CRAVEN : Coward
·       CARPING : tending to make petty complaints; fault-finding. nit packing; captious

·       SAGE :Seer
·       CONNUBIAL
·       PRESCIENT: person having foreknowledge of events
·       MISSIVE : written communication, letter, epistle
·       AMELIORATION : to make better or more tolerable
      trying to ameliorate the suffering of people who have lost their jobs
      This medicine should help ameliorate the pain.
·       ALACRITY
·       ASSUAGE
·       PEJORATIVE : Disparaging, belittling or derogatory, dissed
·       HOLLER : to shout, to yell
·       GARNER
·       BLAND
·       LATENT
·       JADED : Worn out; wearied
·       INGRATIATE : bring oneself into favor with someone by flattering or
trying to please them
·       EXTORTIONATE : extremely expensive, exacting  (extortionate costs may affect project)
·       LAMPOON : a harsh satire, ridicule
·       SPUNK : courage or spirit, pluck
·       PROVIDENTIAL : marked by foresight , divine intervention ( providential purpose for mankind)
·       DEMEANOUR
·       GENESIS

2003
·       LAMPOON : satire, ridicule
·       NEBULOUS : cloudy, misty, hazy
·       TRUCULENT: Disposed to fight; pugnacious, Expressing bitter
opposition; scathing: a truculent speech
·       TYRO : beginner, rookie.
·       TRACTABLE: Easily managed or controlled; governable
·       ETHERAL: Characterized by lightness and insubstantiality; intangible. delicate
·       RICKETY : Tatterdemalion, Ramshackle, Dilapidated
·       STARK : Wholly; entirely; absolutely
·       IMPROVIDENT: not given careful consideration; shortsighted; not foreseeing or providing for the future; negligent; thoughtless
·       ADJUDICATE : To hear and settle (a case) by
judicial procedure.
·       OSTRACIZE : To banish from society; to put under the
ban; pariah
·       CAPTIOUS : Marked by a disposition to find and point out trivial faults: a captious
scholar
·       TOUR DE FORCE : A feat requiring great virtuosity or
strength, often deliberately undertaken for its difficulty
·       TRENCHANT : Forceful, effective, and vigorous: a trenchant
argument
      Caustic; cutting: trenchant criticism

2002
·       Surveillance, Instill, Conservation, Coincide, Retreat, Tentative, Adopted, Impromptu,Reluctantly,Abadon

2001
·       Spectacular, Deteriorating, Refurbished, Infiltrated, Fastidious, Pernicious, Precarious, Recklessly, Adverse ,Altruistic
2000
·       Surreptitious, Remonstration (Argue, Protest), Sanguine, Ramification, Supercilious (haughty, disdain), Obscured, Craftiness, Placate, Adversaries, Cogent

2011
·       Diffidence (Shy, timid) , Superficial, Reckless, Scorn, Grandiose, Judicious, Transpired, Obstinate, Emulate, Trivial, Lurid, Loquacious, Unscrupulous, Confiscate, Sundry, Menial, Impetus.

Lurid : glowing through haze; shocking; sensational;
appalling; horrible.
Example
1. A lurid sun shone upon them as they watched the
sun set.
2. Marked by sensationalism: a lurid account of the crime
3. Glowing or shining with the glare of fire through a haze: lurid flames

Livid: Angry

Dissed:  We have privately dissed(disparage, belittle, affront, show disrespect) their parents, reassuring ourselves that we'd not be such a wimp
(coward, timid)

Canoodle : I love to canoodle( act of love making, caressing etc ) with my girlfriend in public.

Mooching: act of taking advantage of another person., try or obtain by begging.

Subterfuge : Deceit, blind,
Something intended to misrepresent the true nature of an activity; "he wasn't sick--it was just a subterfuge"

Clobbered: 1. To strike
violently and repeatedly; batter or maul. 2. To defeat decisively. 3. To criticize
harshly.


-He was clobbered to death by four unidentified men.