3 jan 2015

7/21/2019 3 JAN 2015

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JAN 2015 MET

1. Which allow to equalise power factr of two alternatr sure

A.govrnr.auto!atic voltage regulatr

".s#ncroscope

$.....

2. %or faithful a!plification& a transistor !ust ' sure

A. (nput forwar) *iase)

. +utput reverse *iase)

". Wor, in operating point

$. All of a*ove

-. Which trip is present in e!ergenc# generator sure

a. +ver voltage trip

*. /n)er voltage trip

c. +ver spee) trip

). None

5.Which of the following are true a*out a te!p !easuring c,t e!plo#e) in in a )ata logger s#ste!

1. A Wheatstone *ri)ge can *e use) in conunction with a Wheatstone *ri)ge in)uction ther!o!eter

2. Ther!o!eter is energie) using a constant current source an) voltage )evelope) is !easure) in

potentio!eter t#pe !etho) $+/T

. (n)uctance of ther!o!eter will change with change in te!p

a. 1 onl#

*. 2 onl#

c. 1 3 2 onl#

). 1 3 onl#

e. 2 3 onl#

4. secon)ar# r!s voltage of full wave rectifier is 125v& what is r!s output voltage 1252

The total secon)ar# voltage in a center6tappe) full6wave rectifier is 1257r!s.Neglecting the )io)e )rop&the r!s output voltage is

8a9 1257 8*9 1::7 8c9 1007 (d) 62.5V

:.The *asic control action of a !agnetic a!plifier )epen)s upon ;;;;;;;;;;;;;. </=E

8a9 variations in the loa) capacitance

8*9 changes in in)uctance

8c9 t#pe of core !aterial

8)9 construction of the core

>. which of the following is true for s#ncronoscope 8!cq9 SUREA. one of the coil in the ar!ature is fe) through a capacitor while other is through resistance

. the coil pro)uces a three phase rotating fiel)

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". the rotating ar!ature has two coils win)ings perpen)icular to each other.

$. The fiel) pro)uces *# the coils rotates the !agnetic ar!ature pointer at a spee) relative to the

frequenc# of the *us *ar suppl#

E. The coils pro)uce a single phase rotating fiel).

?. The value of open loop circuit 1.0 a))e) with real value with curve 666sta*le66666666666 phase sure

10. which of the following is true regar)ing )istri*ution s#ste! on tan,ers sure

a.high voltage )istri*ution s#ste! not allowe) on tan,ers

*.earthe) neutral s#ste! use).

c..,v a*ove insulate) neutral s#ste! use) fw) of the engine roo! *ul,hea)

).none of the a*ove

11.sine wave r!s value 100v ri)ing on 50v)c calculate !a@ value of the resulting wavefor! ans

1-1.- or 1?1.- sure

12. %in) the a!ps require) *# the electrical *ul*&if the elecrton!a,es 10 !oves a*out 22

elecrtons in one hour.assu!e a charge at electron *e 61.40210B1?.

AN< .--5

C1010B22 @ 1.4@10B861?9 D 400 0.--- Answer sure

1. A tur*ocharger has a rate) output of 1200 FW at 40 Gwith no loa) frequenc# of 41.5 h. what

is its spee) )rop

1-. Which of the following isare necessar# precaution8s9 for paralleling an A" Henerator with live

*us *ars sure

(. Henerator frequenc# shoul) *e close to *ut slightl# lower than *us *ar frequenc#

((. Henerator voltage shoul) *e equal to *us *ar voltage

(((. "urrent in generator circuit shoul) *e less than *us *ar current

(7. Henerator voltage shoul) *e in phase with *us *ar voltage

A. (& ((& ((( an) (7

.(& (( an) (7

". (& (( an) (((

$. (( an) (7 onl#

15. When tow generators are running in parallel an) fiel) of one of the! is wea,ene) too !uch

then it will sure

a9 )eliver large share of the total loa)

8*9 )eliver s!all share of the total loa)

8c9 run in the opposite )irection

8)9 run as a !otor in the sa!e )irection

14. fin) the current through a light *ul* fro! a stea)# !ove!ent of electrons in 0.25 hours

Assu!e the charge of single electron 61.402@10B61? coulo!*s8correct to )eci!el9

1:.which of the following are *enefits of !o)if#%("AT(+N +% war) leonar) control s#ste! *#

replacing the !otor set with a th#ristor spee) controller8!cq9 sure

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A.enhance) spee) regulation *# !a,ing the !otor accelertion unifor!

. increases efficienc# of s#ste! especiall# lightl# loa)e)

". e)uces the overall cost of the s#ste!

$. re)uces s#ste! !aintainance

E. increases operating spee) range of s#ste!

%. re)uces overall space require)

1>. the con)uctive loop of the rotor of a si!ple two poles&single phase generator rotates at -00

rps.cal the frequenc# in)uce) output voltage

1?. "alculate avg value of 12 v pea, sign wave for one co!plete c#cle

20. electrons an) protons of the sa!e !o!entu! enter nor!all# into a unifor! !agnetic fiel) of

flu@ )ensit# . !ass of the electron is !e 8! suffi@ e9 an) !ass of the proton is !p 8! suffi@ p9.if

re 8r suffi@ e9 an) rp 8r suffi@ p9 represents the ra)ii of the path of the electrons an) the protons

respectivel#. calculate the ratio rerp. #our answer shoul) *e correct to 2 )eci!als 1.00 sure

20. <e!i con)uctors faile) to over current reason low *rea,)own voltage an)

;overheating;;;;;;;;

21. An insulation resistance rea)ing is ta,en at 20I" foun) to *e 10 !egaoh!. What shoul) *e the

e@pecte) rea)ing at -0I" 2.5 sure

22. JT transistor use) as an a!plifier it operats in sure

a.cut off

*.wellsaturationc.well insaturation

). active region

2. a!*ient te!perature rise in transistor sure

a. life loss

*.life increases

c.sta*le

)

2-.fuse !aterial zinc, copper, silver, aluminum, or alloys sure

a.lea) & inc & tin & allo# of inc& allo# of lea) *.

c.

).

25. %or a J%ET the change in )rain current for a given change in gate to the source voltage

24.the a!ount of current nee)e) for full protection in case of iccp s#ste! for a particular ship will

*e !ost effecte) *# sure

a. wette) surface area

*.qualit# an) con)ition of protection pain coatingc.spee) of the ship

).sea water te!perature

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2:. which of the following consi)er to *e the safest protectioon fro! static electricit# )ischaarge

when connecting or )isconnecting cargo hose an) !etal ar!s </=E

a.insulatiing flange on the length of the non con)ucting hose

*.switching off (""c.ship shore *on)ing ca*le

).non of this a*ove

."lass A a!plifier couple) with transfor!er wat will *e efficienc#...... </=E

A950

9:>.5

hints actuall# less than -0K

2>. "lass A a!plifer percentage </=Ea. :>.>K

*.50K

c.25K

).:5K

A!plifier Ma@i!u! Theoretical

Efficienc#& max

"lass A 25K

"lass :>.5K

"lass " ??K

2?. (n properl# *iase) npn transistor !ost free electron fro! e!!iter </=E

a.reco!*ine with hole an) *ase

*.reco!*ine with e!itter itself

c.stoppe) with e!itter itself

).pass through the *ase to collector

0.The *asic control action of a !agnetic a!plifier )epen)s upon ;;;;;;;;;;;;;. </=E

8a9 variations in the loa) capacitance

7/21/2019 3 JAN 2015


8*9 changes in in)uctance

8c9 t#pe of core !aterial

8)9 construction of the core

1. co!!on e!itter a!plifier is charaterstic *#. </=E

a. low voltage gain

*. !o)rate power factor c.single phase reversal

).ver# high output i!pe)ence

2. (n cc transistor collector a!plifier voltage gain </=E

a. cannot e@cee) unit#

*.)epen)s on out put i!pe)ence

c.)epen)s on out put signel

). alwa#s constant

.which of the following ture regar)s to s#ncronoscope SURE

a. the coil pro)uce phase rotating fiel) *.the coil pro)uce a 2 phase rotating fiel)

c.the coil pro)uce 1 phase rotating fiel)

). the rotating ar!ature has 2 coil win)ing perpen)icular to each other

e.the rotating ara!ature has coil parallel to each other

-. convert 0.04, into............!v </=E

ans 40000!v

5.charterstic of laer light </=E

a.cohernc#

*.coli!ation

c.!onochorocit#

).all the a*ove

4. which of the following use) in earth neutral s#ste! SURE

a.neuttral earthing resistorI

*.fuse

c.overcurrent

).transfor!er

4. *atter# storage </=E

a.preention of electrol#te spillage

*.eas# accessce*le fro! top for !aintences

c.*t ,ept on woo) or tra#

). al,aline an) lea) aci) *atter# are ,ept in seperate roo!

e.*t *an,s !ore than 2,w ,ept in proper cover

:. phase insulate) earth s#ste! one of the path contact with hull sure

a.earthe)

*.short crt or groun)e)c. a an) *

).none of the a*ove

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>.which of the )evice protect the generator overloa) </=E

a. rela# on switch

*.governor

c.A"

).overspee) trip on pri!e!over

?. which is true </=E

a.over current rela# act faster than tuse

*.over current rela# trip the contector on over loa) )epen) on over loa) setting

c.fuse !ent for protection again over loa) uptostale) current

).none of these a*ove

-0.if fan )rawn 14,w at >00rp! an) the rp! re)uce) to 400 rp! than at how !uch ,w of fan

)rawing </=E

A2 ,w

*.4.: ,w answr

c.21.5 ,w).12 ,w

-1. n t#pe se!icon)uctor )opping su*stance </=E

a.anto!#

*.phospors

c.arsecnic

).all the a*ove

-2.class a!plifier </=E

a.)istroation free

*.out put of full wave rectifier

c. out put of half wave rectifier

).

-.capacitor reactance an) resistor are connecte) with sine wavw generate) in series& if the

frequenc# changes what will *e the c apacitor an) resistor value </=E

a.capacitor increase an) resistor )ecrese

*.resistor increase an) capacitor )ecrease

c.*oth not change

).can *e u)ge

--. J%ET s!all changes in )rain an) source voltage with constant )rain current is 66666619 Transconductance 2) pinch off voltage

66666666

-5. while )opping the se!icon)uctor is a))ing i!purites& wh# it is calle) i!purities </=E

a.it change the cr#stal structure of the se!icon)uctor

*.it change the che!ical free se!icon)uctor

c.it prevent the flow olow of free electrons

).

-4. which of the following state!ent is false for lea) aci) *atter#. </=E

A. when )ischarge *oth positive an) negative plate contain lea) sulphate

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*.when charge) negative plate contain spong# lea)

c.when charge) positive plate lea) per o@i)e

).when )ischarge electrol#te un)ergose no che!ical reaction

-:. output of class a!plifier </=E

a.)istroration free

*.consiste positive half c#clec.li,e output of full wave rectifier

). co!prise of short )uration current pluses

->. woun) rotor !otor changing the spee) troque charteristic control an) spee) control perpose

a.use A7= with !otor SURE

*.use changing no of poles in a !otor

c.use e@ternal resistor in a rotor circuit

)..use e@ternal resistor in a stator circuit

e.th#ristor in co!*ine with !otor.

-?.which of the following prevents !oisture con)ensation in a weather)ec, switch *oar) </=E1.installing light *lu* in pe)estal stan)

2.coat internal of switch *o@ With epo@# seale)

.venting the switch*oar) regularl#.

- using strip heater

a . 2 an) -

*. onl# -

c. 1&2&&-

). an) 2

50. groung occur in the electrical !achiner# as a result of insulation failure. </=E

a.)eteration through !oisture

*.e@cessie heater

c.e@ternal perio) of vi*ration

). all of the a*ove

51. unique fuature of a cc tranistor a!plifer circuit is </=E

a.step up the i!pe)ence level

*.)ose not increase the signal voltage

c.act as a i!pe)ence !atching )evice

).all of the a*ove

G(NT< http'www.alla*outcircuits.co!vol;chpt;-4.ht!l

52. capasitor an) resistor connecte) in series with the sine wave generator frequenc# is set so that

the capacitor reactances is equal to the resistance an) thus equal a!ount of voltage appearse across

each co!ponent & what happen when frequenc# </=E

a.voltage across the resistor *eca!e higher than voltage in the capacitor

*.voltage across the capacitor *eaca!e higher than voltage in the resistor

c.voltage across ccapacitor re!ain sa!e as the voltage across the resistor

).cannot )eter!ine

5.a)vantage of ni,el can)!iu! *atter# SURE

http://www.allaboutcircuits.com/vol_3/chpt_4/6.html

http://www.allaboutcircuits.com/vol_3/chpt_4/6.html

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a.high voltage

*.fewer cell nee)e) for sa!e voltage

c.full charge for long ti!e

). less e@pensive

5-. open loop 1.0 positive real value666666<TALE GA<E66666666666666 SURE

55. phase& if it is connecte) insulate) neutral earth s#ste! to the ship hull

a.short crt

*.earth fault

c.*oth a an) *

).neither a or *

55. pn unction a)vantages

a.

*.

c.). all of the a*ove

54.what will *e in !otor & for electro steering gear

a.fuse

*.overloa) alar!

c.overloa) trip

).power failure alar!

note6 c) Motor alarm : A visual and audible alarm is to be given on the navigating bridge and the engine room

control station to indicate an overload condition of the steering gear power unit motor. Where three phase electrical

power is used a visual audible alarm is to be installed which indicates failure of any one of the supply phases. Theoperation of these alarms is not to interrupt the circuit.

e) Power failure : A visual and audible alarm is to be given on the navigating bridge and engine room controlstation to indicate a power failure to any one of the steering gear power units.

5:.i!purities in se!icon)uctor </=E

a.)opping

*.*iasing

c.allo#ing

).none of the a*ove

58. Due to which of the following reasons a separately excited generator as compared to a self-excited

generator is better? SURE

(a) is more stable

(b) has ex citing current in dependent of load current

(c) is amenable to better voltage

(d) has all above features

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59. If a shunt generator fails to build up any voltage at no-load, the reason may be that.

(a) there is no residual magnetism .

(b) field coil may be connected in reverse direction

(c) field resistance is more than the critical resistance

(d) all or anyone of the above.

A is true (A shunt generator may not develop its rated operating voltage due to a loss of residual magnetism)

B is true (If field current is reversed it opposes the residual magnetism and consequently no voltage build up takes place)

C is true (Critical resistance is that resistance at which a shunt generator just builds voltage. Any increase in its value and

the generator fails to build voltage)

answer is d

60. If the pointer fails to return to zero when a megger is disconnected, the_____________. SURE• pointer is stuck

• hair springs are burned out

• megger is out of calibration

• megger is operating normally

Which of the following d.c. generator can build up without anyresidual magnetism SURE

A.Compound generator

B.Self-excited generator

C.Series generator

D.Shunt generator

58. The output voltage of a simple d.c. generator is SURE

(a) a.c. square wave.

() a.c. sinusoidal wave

(c) pure d.c!

(d) pulsating d.c.

The commutator segments of a d.c. machine are made of SUREA.Carbon

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A control action whichproduces a correctivesignal relative to thespeed at which thecontrolled variable ischanging is nownas .

reset actionintegral

action

derivative

action

proportional

action

3) In an AC synchronous motor electric propulsion plant, propeller speed is

controlled by varying the _____________.USC

A)prime mover speed

!) electric coupling "ield strength

C) number o" energi#ed main motor poles

$)propulsion generator "ield strength

3 jan 2015

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