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8/17/2019 Obj EEE For FE.docx

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1. A sine wave has a frequency of 50 Hz. Its angular frequency is_______ radian/second.

(a 100 n (! 50 "t

(c #5 "t(d 5 n

Ans$ a

#. %he reactance o&ered !y a ca'acitor to alternating current offrequency 50 Hz is #0 . If frequency is increased to 100 Hz)reactance !eco*es_____oh*s.(a #.5 (! 5

(c 10 (d 15

Ans$ c

+. %he 'eriod of a wave is(a the sa*e as frequency(, ti*e required to co*'lete one cycle(c e-'ressed in a*'eres(d none of the a!ove

Ans$ !

. %he for* factor is the ratio of (a 'ea value to r.*.s. value(, r.*.s. value to average value(c average value to r.*.s. value(d none of the a!ove

Ans$ !

5. %he 'eriod of a sine wave is _____ seconds.Its frequency is(a #0 Hz

(! +0 Hz(c 0 Hz (d 50 Hz

Ans$ d


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,. A heater is rated as #+0 ) 10 ) A.2. %he value #+0 refers to(a average voltage(! r.*.s. voltage(c 'ea voltage(d none of the a!ove

Ans$ !

3. If two sinusoids of the sa*e frequency !ut of di&erent a*'litudesand 'hase angles are su!tracted) the resultant is(a a sinusoid of the sa*e frequency(! a sinusoid of half the original frequency(c a sinusoid of dou!le the frequency(d not a sinusoidAns$ a

4. %he 'ea value of a sine wave is #00 . Its average value is

(a 1#3. (! 11. (c #4#.4 (d#00Ans$ a

. If two sine waves of the sa*e frequency have a 'hase di&erenceof 6% radians) then(a !oth will reach their *ini*u* values at the sa*e instant(! !oth will reach their *a-i*u* values at the sa*e instant(c when one wave reaches its *a-i*u* value) the other will reach

its *ini*u* value(d none of the a!oveAns$ c

10. %he voltage of do*estic su''ly is ##0. %his 7gure re'resents(a *ean value(! r.*.s. value(c 'ea value (d average valueAns$ a

11. %wo waves of the sa*e frequency have o''osite 'hase when the'hase angle !etween the* is(a +,08 (! 1408(c 08 (d 08Ans$ !


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1#. %he 'ower consu*ed in a circuit ele*ent will !e least when the'hase di&erence !etween the current andvoltage is

(a 1409 (! 08(c ,08 (d 08Ans$ !

1+. %he r.*.s. value and *ean value is the sa*e in the case of (a triangular wave(, sine wave (c square wave(d half wave recti7ed sine wave

Ans$ c

1. :or the sa*e 'ea value which of the following wave will ;havethe highest r.*.s. value <(a square wave(! half wave recti7ed sine wave(c triangular wave(d sine waveAns$ a

15. :or the sa*e 'ea value) which of the following wave has the

least *ean value <(a half wave recti7ed sine wave(! triangular wave(c sine wave (d square waveAns$ a

1,. :or a sine wave with 'ea value I*a- the r.*.s. value is(a 0.5 I*a- (! 0.303(c 0.

(d 1.1 =*a-Ans$ !

13. :or* :actor is the ratio of (a average value/r.*.s. value(! average value/'ea value(e r.*.s. value/average value(d r.*.s. value/'ea value


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Ans$ c

14. :or* factor for a sine wave is(a 1.1 (! 0.303

(c 1.11 (d 0.,+3Ans$ c

1. :or a sine wave with 'ea value >*a-______4.+0. the averagevalue is(a 0.,+, >*a- (! 0.303 >*a-(c 0.+ >c (d lA?>*a-Ans$ a

#0. :or a frequency of #00 Hz) the ti*e 'eriod will !e(a 0.05 s (! 0.005 s(c 0.0005 s (d 0.5 sAns$ !

#1. %he 'hase di&erence !etween voltage and current wave througha circuit ele*ent is given as +08. %he essential condition is that(a !oth waves *ust have sa*e frequency

(! !oth waves *ust have identical 'ea values(c !oth waves *ust have zero value at the sa*e ti*e(d none of the a!oveAns$ a

##. %he r.*.s. value of a sinusoidal A.2. current is equal to its valueat an angle of______degrees.(a 0 (! ,0(c 5 (d +0

Ans$ c

#+. 2a'acitive reactance is *ore when(a ca'acitance is less and frequency of su''ly is less(! ca'acitance is less and frequency of su''ly is *ore(c ca'acitance is *ore and frequency of su''ly is less(d ca'acitance is *ore and frequency of su''ly is *oreAns$ a


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#. In a series resonant circuit) the i*'edance of the circuit is(a *ini*u* (! *a-i*u*(c zero

(d none of the a!oveAns$ a

#5. @ower factor of an electrical circuit is equal to(a /B(! cosine of 'hase angle di&erence !etween current and voltage(c /A(d ratio of useful current to total current Iw/I(e all a!oveAns$ e

#,. %he !est 'lace to install a ca'acitor is(a very near to inductive load(! across the ter*inals of the inductive load(c far away fro* the inductive load(d any whereAns$ !

#3. @oor 'ower factor(a reduces load handling ca'a!ility of electrical syste*(! results in *ore 'ower losses in the electrical syste*(c overloads alternators) transfor*ers and distri!ution lines

(d results in *ore voltage dro' in the line(e results in all a!oveAns$ e

#4. 2a'acitors for 'ower factor correction are rated in(a (! A(c (d AAns$ d

#. In series resonant circuit) increasing inductance to its twicevalue and reducing ca'acitance to its half value(a will change the *a-i*u* value of current at resonance(, will change the resonance frequency(c will change the i*'edance at resonance frequency(d will increase the selectivity of the circuitAns$ d


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+0. @ure inductive circuit(a consu*es so*e 'ower on average(! does not tae 'ower at all fro* a line(c taes 'ower fro* the line during so*e 'art of the cycle and thenreturns !ac to it during other 'art of the cycle

(d none of the a!oveAns$ c

+1. Inductance a&ects the direct current Cow(a only at the ti*e of turning o& (! only at the ti*e of turning on(c at the ti*e of turning on and o& (d at all the ti*e of o'erationAns$ c

+#. Inductance of a coil aries

(a directly as the crossDsectional area of *agnetic core(! directly as square of nu*!er of turns(c directly as the 'er*ea!ility of the core(d inversely as the length of the iron 'ath(e as (a to (dAns$ e

++. All the rules and laws of E.2. circuit also a''ly to A.2. circuitcontaining(a ca'acitance only(! inductance only

(c resistance only(d all a!oveAns$ c

+. %i*e constant of an inductive circuit(a increases with increase of inductance and decrease of resistance(! increases with the increase of inductance and the increase ofresistance(c increases with decrease of inductance and decrease ofresistance(d increases with decrease of inductance and increase of resistance

Ans$ a

+5. @ower factor of an inductive circuit is usually i*'roved !yconnecting ca'acitor to it in(a 'arallel (! series(c either (a or (!(d none of the a!ove


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Ans$ a


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+,. In a highly ca'acitive circuit the(a a''arent 'ower is equal to the actual 'ower(! reactive 'ower is *ore than the a''arent 'ower(c reactive 'ower is *ore than the actual 'owetf

(d actual 'ower is *ore than its reactive 'owerAns$ c

+3. @ower factor of the following circuit will !e zero(a resistance (! inductance(c ca'acitance(d !oth (! and (cAns$ d

+4. @ower factor of the following circuit will !e unity

(a inductance (! ca'acitance(c resistance (d !oth (a and (!Ans$ c

+. @ower factor of the syste* is e't high(a to reduce line losses(! to *a-i*ise the utilization of the ca'acities of generators) linesand transfor*ers(c to reduce voltage regulation of the line

(d due to all a!ove reasonsAns$ d

0. %he ti*e constant of the ca'acitance circuit is de7ned as theti*e during which voltage(a falls to +,.4F of its 7nal steady value(! rises to +4.,F of its 7nal steady value(c rises to ,+.#F of its 7nal steady value(d none of the a!oveAns$ c

1. In a lossDfree D=D2 circuit the transient current is(a oscillating (! square wave(c sinusoidal (d nonDoscillatingAns$ c


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#. %he r.*.s. value of alternating current is given !y steady (E.2.current which when Cowing through a given circuit for a given ti*e'roduces(a the *ore heat than 'roduced !y A.2. when Cowing through the

sa*e circuit(! the sa*e heat as 'roduced !y A.2. when Cowing through thesa*e circuit(c the less heat than 'roduced !y A.2. Cowing through the sa*ecircuit(d none of the a!oveAns$ !

+. %he square wavefor* of current has following relation !etweenr.*.s. value and average value.(a r.*.s. value is equal to average value

(! r.*.s. value of current is greater than average value(c r.*.s. value of current is less than average value(d none of the a!oveAns$ a

. %he dou!le energy transient occur in the(a 'urely inductive circuit(! D= circuit(c D2 circuit(d D=D2 circuitAns$ d

5. %he transient currents are associated with the(a changes in the stored energy in the inductors and ca'acitors(! i*'edance of the circuit(c a''lied voltage to the circuit(d resistance of the circuitAns$ a

,. %he 'ower factor at resonance in D=D 2 'arallel circuit is(a zero (! 0.04 lagging

(c 0.4 leading (d unityAns$ d

3. In the case of an unsy**etrical alternating current the averagevalue *ust always !e taen over(a unsy**etrical 'art of the wave for*(! the quarter cycle


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(c the half cycle(d the whole cycleAns$ d

4. In a 'ure resistive circuit

(a current lags !ehind the voltage !y 08(! current leads the voltage !y 08(c current can lead or lag the voltage !y 08(d current is in 'hase with the voltageAns$ d

. In a 'ure inductive circuit(a the current is in 'hase with the voltage(! the current lags !ehind the voltage !y 08(c the current leads the voltage !y 08(d the current can lead or lag !y 08

Ans$ !

50. In a circuit containing ) = and 2) 'ower loss can tae 'lace in(a 2 only (! = only(c only (d all a!oveAns$ c

51. Inductance of coil(a is una&ected !y the su''ly frequency

(! decreases with the increase in su''ly frequency(c increases with the increase in su''ly frequency(d !eco*es zero with the increase in su''ly frequencyAns$ c

5#. In any A.2. circuit always(a a''arent 'ower is *ore than actual 'ower(! reactive 'ower is *ore than a''arent 'ower(c actual 'ower is *ore than reactive 'ower(d reactive 'ower is *ore than actual 'owerAns$ a

5+. hich of the following circuit co*'onent o''oses the change inthe circuit voltage <(a Inductance(! 2a'acitance(c 2onductance(d esistance


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Ans$


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5. In a 'urely inductive circuit(a actual 'ower is zero(! reactive 'ower is zero(c a''arent 'ower is zero

(d none of a!ove is zeroAns$ a

55. @ower factor of electric !ul! is(a zero (! lagging(c leading (d unityAns$ d

5,. @ure inductive circuit taes 'ower fro* the A.2. line when

(a a''lied voltage decreases !ut curGrent increases(! a''lied voltage increases !ut curGrent decreases(c !oth a''lied voltage and current increase(d !oth a''lied voltage and current decreaseAns$ a

53. %i*e constant of a circuit is the ti*e in seconds taen after thea''lication of voltage to each(a #5F of *a-i*u* value(! 50F of *a-i*u* value(c ,+F of *a-i*u* value

(d 0F of the *a-i*u* valueAns$ c

54. %i*e constant of an inductive circuit(a increases with increase of inductance and decrease ofresistance(! increases with the increase of inductance and the increase ofresistance(c increases with the decrease of inductance and decrease ofresistance(d increases with decrease of inductance and increase of resistance

Ans$ a

5. %i*e constant of a ca'acitive circuit(a increases with the decrease of ca'acitance and decrease ofresistance(! increases with the decrease of ca'acitance and increase ofresisGtance(c increases with the increase of ca'acitance and decrease of


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resisGtance(d increase with increase of ca'acitance and increase ofresisGtanceAns$ d


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,0. agnitude of current at resonance in D=D2 circuit(a de'ends u'on the *agnitude of (! de'ends u'on the *agnitude of =(c de'ends u'on the *agnitude of 2

(d de'ends u'on the *agnitude of ) =and2Ans$ a

,1. In a D=D2 circuit(a 'ower is consu*ed in resistance and is equal to I (! e-change of 'ower taes 'lace !etween inductor and su''ly line(c e-change of 'ower taes 'lace !etween ca'acitor and su''lyline(d e-change of 'ower does not tae 'lace !etween resistance andthe su''ly line(e all a!ove are correct

Ans$ e

,#. In D=D2 series resonant circuit *agnitude of resonancefrequency can !e changed !y changing the value of (a only (! = only(c 2 only (d = or 2(e )= or 2Ans$ d

,+. In a series =D2 circuit at the resonant frequency the(a current is *a-i*u*(! current is *ini*u*(c i*'edance is *a-i*u*(d voltage across 2 is *ini*u*Ans$ a

,. %he ti*e constant of a series D2 circuit is given !y(a /2 (! 2#(c 2

(d #2Ans$ c

,5. If resistance is #0 . and inductance is #3 in a D= series circuit)then ti*e constant of this circuit will !e(a 0.001 s (! 0.1 s(c 10 s


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(d 100 sAns$ !

,,. hich of the following coil will have large resonant frequency <(a A coil with large resistance

(! A coil with low resistance(c A coil with large distri!uted ca'acitance(d A coil with low distri!uted ca'acitanceAns$ c

,3. If a sinusoidal wave has frequency of 50 Hz with +0 A r.*.s.current which of the following equation re'resents this wave <(a #.# sin +11(! ,0 sin #5 t(c +0 sin 50 t (d 4.4 sin #5 t

Ans$ a

,4. %he safest value of current the hu*an !ody can carry for *orethan + second is(a *A (! *A(c 15 *A (d #5 *AAns$ !

,. A 'ure inductance connected across #50 ) 50 Hz su''ly

consu*es 100 .%his consu*'tion can !e attri!uted to(a the !ig size of the inductor(! the reactance of the inductor(c the current Cowing in the inductor(d the state*ent given is falseAns$ d

30. %he in'ut of an A.2. circuit having 'ower factor of 0.4 lagging is0 A%he 'ower drawn !y the circuit is

(a 1# (! ## (c +# (d , Ans$ c


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31. %he e&ective resistance of an ironDcored choe woring onordinary su''ly frequency is *ore than its true resistance !ecauseof (a iron loss in core

(! sin e&ect(c increase in te*'erature(d ca'acitive e&ect !etween ad"acent coil turnsAns$ a

3#. In an A2. circuit) a low value of A co*'ared with indicates(a low eciency(! high 'ower factor(c unity 'ower factor(d *a-i*u* load current

Ans$ !

3+. In A2. circuits) la*inated iron is invaria!ly used in order to(a reduce eddy current loss(! increase heat radiation(c *ae asse*!ly chea' and easier(d reduce circuit 'er*ea!ilityAns$ a

3. %he ratio of active 'ower to a''arent 'ower is nown as factor.(a de*and

(! load(c 'ower (d for*Ans$ c

35. All de7nitions of 'ower factor of a series D=D2 circuit are correcte-ce't(a ratio of net reactance and i*'edance(! ratio of and A(c ratio of 6 and B(d ratio of and A

Ans$ a

3,. %he a''arent 'ower drawn !y an A.2. circuit is 10 A andactive 'ower is 4 . %he reactive 'ower in the circuit is(a A (! , A(c 4 A (d 1, A


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Ans$ !

33. hat will !e the 'hase angle !etween two alternating waves ofequal frequency) when one wave attains *a-i*u* value the other isat zero value <

(a 08 (! 58(c 08 (d 1408Ans$ c

34. %he 'ur'ose of a 'arallel circuit resonance is to *agnify(a current (! voltage(c 'ower (d frequency

Ans$ !

3. In an A.2. circuit 'ower is dissi'ated in(a resistance only(! inductance only(c ca'acitance only(d none of the a!oveAns$ a

40. In a 'arallel D2 circuit) the current always______the a''liedvoltage

(a lags (! leads(c re*ains in 'hase with(d none of the a!oveAns$ !

41. At very low frequencies a series D2 circuit !ehaves as al*ost'urely (a resistive (! inductive(c ca'acitive


4#. Jin e&ect occurs when a conductor carries current at_____ frequencies.(a very low (! low(c *ediu*


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(d highAns$ d


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4+. At ______ frequencies the 'arallel D= circuit !ehaves as 'urelyresistive.(a low

(! very low(c high (d very highAns$ d

4. In a sine wave the slo'e is constant(a !etween 08 and 08(! !etween 08 and 1408(c !etween 1408 and #308(d no whereAns$ d

45. %he 'ower is *easured in ter*s of deci!les in case of (a electronic equi'*ent(! transfor*ers(c current transfor*ers(d auto transfor*ersAns$ a

4,. 2a'acitive susce'tance is a *easure of (a reactive 'ower in a circuit(! the e-tent of neutralisation of reactive 'ower in a circuit

(c a 'urely ca'acitive circuit;s a!ility to 'ass current(d a 'urely ca'acitive circuit;s a!ility to resist the Cow of currentAns$ c

43. hich of the following state*ents 'ertains to resistors only <(a can dissi'ate considera!le a*ount of 'ower(, can act as energy storage devices(c connecting the* in 'arallel inGcreases the total value(d o''ose sudden changes in voltageAns$ a

44. hich of the following refers to a 'arallel circuit <(a %he current through each ele*ent is sa*e(! %he voltage across ele*ent is in 'ro'ortion to it;s resistancevalue(c %he equivalent resistance is greater than any one of the resistors(d %he current through any one ele*ent is less than the sourcecurrent


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Ans$ d


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4. A'hasoris(a a line which re'resents the *agGnitude and 'hase of analternating quantity(! a line re'resenting the *agnitude and direction of an

alternating quantity(c a coloured tag or !and for distinction !etween di&erent'hases of a +D'hase su''ly(d an instru*ent used for *easuring 'hases of an un!alanced +D'hase loadAns$ a

4. A 'arallel A2. circuit in resonance will(a have a high voltage develo'ed across each inductive andca'acitive section(! have a high i*'edance

(c act lie a resistor of low value(d have current in each section equal to the line currentAns$ !

0. ireDwound resistors are unsuita!le for use at high frequencies!ecause they(a create *ore electrical noise(! are liely to *elt under e-cessive eddy current heat(c consu*e *ore 'ower(d e-hi!it unwanted inductive and ca'acitive e&ectsAns$ d

1. %he inductance of a coil can !e increased !y(a increasing core length(! decreasing the nu*!er of turns(c decreasing the dia*eter of the for*er(d choosing core *aterial having high relative 'er*ea!ilityAns$ d

#. In a threeD'hase su''ly Coating neutral is undesira!le !ecauseit way give rise to(a high voltage across the load

(! low voltage across the load(c unequal line voltages across the loadAns$ c

+. hich of the following waves has the highest value of 'eafactor <(a Jquare wave(! Jine wave


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(c Half wave recti7ed sine wave(d %riangular waveAns$ c


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. %he frequency of do*estic 'ower su''ly in India is(a #00 Hz (! 100 Hz(c ,0 Hz

(d 50 HzAns$ d

5. %he r.*.s. value of half wave recti7ed sine wave is #00 . %her.*.s. value of full wave recti7ed A2. will !e(a #4#.4 (! 11. (c 111 (d 100 Ans$ a

,. %he r.*.s. value of 'ure cosine function is(a 0.5 of 'ea value(! 0.303 of 'ea value(c sa*e as 'ea value(d zeroAns$ !

3. Kh* is unit of all of the following e-ce't(a inductive reactance(! ca'acitive reactance(c resistance

(d ca'acitanceAns$ d

4. %he series Lnd 'arallel resonance on =D2 circui; di&ers in that(a series resistance needs a lowDresistance ource for shar' rise incurrent(! series resonance needs a highDresistance source for shar'increase in current(c 'arallel resonance needs a lowDresistance source for a shar'inGcrease in i*'edance(d 'arallel resonance needs a lowDresistance source for a shar' rise

in line currentAns$ a

. %he 'hasors for which of the following 'air are 1408 out of 'hasefor =) 2 and <(a c and (! = and (c c and =


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100. %he frequency of an alternating current is

(a the s'eed with which the alternator runs(! the nu*!er of cycles generated in one *inute

(c the nu*!er of waves 'assing through a 'oint in one second

(d the nu*!er of electrons 'assing through a 'oint in one second

Ans$ c

101. A 'ure ca'acitor connected across an A.2. voltage consu*ed 50 .

%his is due to

(a the ca'acitive reactance in oh*s

(! the current Cowing in ca'acitor

(c the size of the ca'acitor !eing quite !ig

(d the state*ent is incorrect

Ans$ d

10#. %he 'ower factor of a E.2. circuit is always

(a less than unity

(! unity

(c greater than unity

(d zero

Ans$ !

10+. %he 'roduct of a''arent 'ower and cosine of the 'hase angle!etween circuit voltage and current is

(a true 'ower

(! reactive 'ower

(c voltDa*'eres

(d instantaneous 'ower

Ans$ a

10. %he equation of 50 Hz current sine wave having r.*.s. value of ,0 A is

(a ,0 sin #5 t

(! ,0 sin 50 t(c 4.4 sin +11

(d #.# sin +1 t

Ans$ c

105. An A.2. voltage is i*'ressed across a 'ure resistance of +.5 oh*s in

'arallel with a 'ure inductance of i*'edance of +.5 oh*s)

(a the current through the resistance is *ore


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(! the current through the resistance is less

(c !oth resistance and inductance carry equal currents

(d none of the a!ove

Ans$ c

10,. In a 'ure inductive circuit if the su''ly frequency is reduced to 1/#)the current will

(a !e reduced !y half

(! !e dou!led

(c !e four ti*es as high

(d !e reduced to one fourth

Ans$ !

103. In a 'ure ca'acitive circuit if the su''ly frequency is reduced to 1/#)

the current will

(a !e reduced !y half

(! !e dou!led

(c !e four ti*es at high

(d !e reduced to one fourth

Ans$ a

104. hen an alternating current 'asses through an oh*ic resistance the

electrical 'ower converted into heat is

(a a''arent 'ower

(! true 'ower

(c reactive 'ower

(d none of the a!oveAns$ !

10. In each of the three coils of a three 'hase generator) an alternating

voltage having an r.*.s. value of ##0 is induced. hich of the following

values is indicated !y the volt*eters <

(a ##0

(! ##0+

(c ##0/+

(d none of the a!ove

Ans$ a

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