K M M INSTITUTE OF TECHNOLOGY & SCIENCE: TIRUPATI I B.TECH I-SEM /EEE / MID – II /EC TIME: 90 MIN DESCRIPTIVETEST MAX.MARKS.30 ANSWER ANY THREE QUESTIONS Each Question Carry equal markers

1.Define conductance, susceptance, admittance and impedance of a ac circuit2.Derive an expression for the impedance of an ac circuit consisting of a resistance and inductance in series3.Acoil of resistance 50ohm and inductance 0.1H is connected in series with a capacitor of 150μf across a 200V, 50 Hz supply. Calculate a) currentb)power factor c)power and voltage across the coil and capacitor.Draw the phasor diagram4.A balanced 3-ⱷ star connected load of 100 kilowatt taken a lagging current of 75Awith line voltage of 1000V,50Hz. Find the circuit constant of the load per phase5.a)state the thevinins theorem .b)Find the current across 10Ω resistor and draw the thevinins equivalent circuit diagram for given below fig

K M M INSTITUTE OF TECHNOLOGY & SCIENCE: TIRUPATII B.TECH I-SEM EEE/ MID – II /EC

TIME: 20 MIN OBJECTIVE TEST MAX. MARKS: 20 REGISTERED NUMBER: ___________ MARKS OBTAINED: ______

1 Super position theorem can be applied only to circuits havinga)resistive elements b)passive elements c)nonlinear elements d)linear bilateral elements

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2 The concept on which super position theorem is based isa)reciprocity b)duality c)nonlinearity d)linearity

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3 Thevinins resistance Rth is founda)by removing voltage sources along with their internal resistance b)by short circuiting the given two terminals c)between any two open terminals d)between same open terminals as for ETK

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4 The power factor of purely resistive circuits isa)zero b)unity c)lagging d)leading

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5 The power taken by 3-phase load is given by the expressiona)3 VLILcosⱷ b)√3VLILcosⱷ c) 3 VLIL sinⱷ d)√3VLIL sinⱷ

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6 In an ac circuit ,the ratio of KW/KVA representsa)power factor b)load factor c)form factor d)diversity factor

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7 In a R-L-C circuitthe phase of current with respect to the circuit voltage will bea)leading b)same c)lagging d)depends up on L and C

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8 The frequency of dc supplya)zero b)16 HZ c)50HZ d)100 HZ

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9 The rms value of sinusoidal 100v peak to peak isa)100/√ 2 b)50/√ 2 c)50 d)100

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10 In India electrical power transmitted bya)1-phase ac system b)3 wire dc system c)3 –phase 3 wire ac system 4)2 wire dc system

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11 In a ac circuit the product of voltage and current is known as a)power b)real power c)resistive power d)apparent power

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12 Watt hour is the unit of a)electric power b)electric capacity c)electric energy d)electric charge

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13 In a two wattmeter method of power measurement if one of the wattmeter shows zero reading, then it can be concluded thata)power factor unity b)power factor zero c)power factor is 0.5 lagging d)power factor is 0.5 leading

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14 Which of the following will remains the same in all parts of circuita)voltage b)current c)power d)resistance

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15 The input of ac circuit having p.f of 0.8 lagging is 20 KVA .The power drawn by circuit is ------- kwa)12 b)20 c)16 d)8

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16 In case of inductive circuit, the frequency is ------ proportional to inductancea)directly b)inversely c)no effect d)none

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17 In inductive circuit when inductance(L) or inductive reactance(XL) increases the ckt current decreases the cktp,fa)increases b)decreases c)remain same d) none of above

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18 In case of capacitive ckt,frequency is -----proportional to the capacitancea)directly b) inversely c)no effect d)none of the above

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19 In capacitive ckt when capacitance(c) or capacitive reactance(Xc)increases the ckt current decreases the cktp,fa)increases b)decreases c)remain same d) none of above

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20 If the current and voltage are 90 degree out of phase ,then the power (p) will be------a)infinite b)maximum c)normal d)zero

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