This is the Multiple Choice Questions Part 7 of the Series in AC Circuits as one of the Electrical Engineering topic. In Preparation for the REE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Exam Questions in Electrical Engineering field, Electrical Engineering Books, Journals and other Electrical Engineering References.

#### Continue Practice Exam Test Questions Part 7 of the Series

SERIES CIRCUITS

**Choose the letter of the best answer in each questions.**

โ MCQ in AC Circuits Part 6 | REE Board Exam

301.ย A circuit component that opposes the change in circuit voltage is

A.ย resistance

B.ย capacitance

C.ย inductance

D.ย all of these

Answer: **Option B**

Solution:

302.ย Power loss in an electrical circuit can take place in

A.ย inductance only

B.ย capacitance only

C.ย inductance and resistance

D.ย resistance only

Answer: **Option D**

Solution:

303.ย A circuit of zero lagging power factor behaves as

A.ย an inductive circuit

B.ย a capacitive circuit

C.ย R-L circuit

D.ย R-C circuit

Answer: **Option A**

Solution:

304.ย In an R-L series circuit the power factor is

A.ย leading

B.ย lagging

C.ย zero

D.ย unity

Answer: **Option B**

Solution:

305.ย When a sinusoidal voltage is applied across an R-L series circuit having R = X_{L}, the phase angle will be

A.ย 90ยฐ

B.ย 45ยฐ lagging

C.ย 45ยฐ leading

D.ย 90ยฐ leading

Answer: **Option B**

Solution:

306.ย Anย acย sourceย havingย voltageย eย =ย 110ย sinย (ฯtย +ย ฯ/3)ย isย connectedย inย anย ac circuit. If the current drawn from the circuit varies as i = 5 sin (ฯtย –ย ฯ/3) the impedance of the circuit will be

A.ย 22 ฮฉ

B.ย 16 ฮฉ

C.ย 30.8ย ย ฮฉ

D.ย none of these

Answer: **Option A**

Solution:

307.ย Which are of the following true of the circuit shown in the given figure?

1.ย V_{R} =ย 100โ2ย Vย ย ย ย ย ย ย 2.ย I = 2 Aย ย ย ย ย 3.ย L = 0.25 H

Select the correct answer using the codes given below:

Codes:

A.ย 2 and 3

B.ย 1 and 2

C.ย 1 and 3

D.ย 1, 2 and 3

Answer: **Option A**

Solution:

308.ย Theย R-Lย circuitย ofย theย figureย isย fedย fromย aย constantย magnitudeย variable frequencyย sinusoidalย voltageย sourceย vin.ย Atย 100ย Hz,ย theย Rย andย Lย element each has a voltage drop Vrms. If theย frequency of the source is changes to 50 Hz, then new voltage drop across R is

A.ย โ(5/8) Vrms

B.ย โ(2/3) Vrms

C.ย โ(8/5) Vrms

D.ย โ(3/2) Vrms

Answer: **Option C**

Solution:

309. Anย ac source of 200 Vrms supplies active power of 600 W and reactive power of 800 VAR. The rms current drawn from the source is

A.ย 10 A

B.ย 5 A

C.ย 3.75 A

D.ย 2.5 A

310.ย A square wave is fed to an R-C circuit. Then

A.ย voltage across R is square and across C is not square

B.ย voltage across C is square and across R is not square

C.ย voltage across both R and C is square

D.ย voltage across both R and C is not square

Answer: **Option D**

Solution:

311.ย Theย voltageย phasorย ofย aย circuitย is 10โ 15ยฐ Vย andย theย currentย phasorย is 2โ -45ยฐ A. The active and reactive powers in the circuit are

A.ย 10 W and 17.32 VAR

B.ย 5 W and 8.66 VAR

C.ย 20 W and 60 VAR

D.ย 20โ2 W andย 10โ2 VAR

Answer: **Option A**

Solution:

312.ย In a two-element series circuit, the applied voltage and resultant current are respectively, v(t) = 50 + 50 sin (5 x 10^{3} t) and i(t) = 11.2 sin (5 x 10^{3} t + 63.4ยฐ). The nature of the elements would be

A.ย R-L

B.ย R-C

C.ย L-C

D.ย neither R, nor L, nor C

Answer: **Option B**

Solution:

313.ย Aย seriesย circuitย passiveย elementsย hasย theย followingย currentย andย applied voltage: v = 200 sin (2,000t + 50ยฐ), i = 4 cos (2,000t + 13.2ยฐ). The circuit elements

A.ย must be resistance and capacitance

B.ย must be resistance and inductance

C.ย must be inductance, capacitance and resistance

D.ย couldย beย eitherย resistanceย andย capacitanceย orย resistance,ย inductance and capacitance

Answer: **Option D**

Solution:

314.ย A two terminal black box contains one of the R-L-C elements. The black box is connected to a 220 V ac supply. The current through the source is I. When a capacitance of 0.1 F is inserted in series between the source and the box, the current through the source is 2I. The element is

A.ย a resistance

B.ย an inductance

C.ย a capacitance

D.ย it is not possible to determine the element

Answer: **Option B**

Solution:

315.ย In the following circuit, i(t) under steady state is

A.ย zero

B.ย 5

C.ย 7.07 sin t

D.ย 7.07 sin (t โ 45ยฐ)

Answer: **Option D**

Solution:

316.ย The source in the circuit is a sinusoidal source. The supply voltages across various elements are marked in the figure. The input voltage is

A.ย 10 V

B.ย 5 V

C.ย 27 V

D.ย 24 V

Answer: **Option B**

Solution:

317.ย In the circuit shown in the given figure, if the power consumed by the 5 ฮฉ resistor is 10 W, then the pf of the circuit is

A.ย 0.8

B.ย 0.6

C.ย 0.5

D.ย zero

Answer: **Option B**

Solution:

318.ย Inย anย RLย circuit,ย suppliedย fromย anย acย source,ย theย reactiveย powerย is proportional to the

A.ย the average energy stored in the electric field

B.ย the average energy stored in the magnetic field

C.ย sum of the average energy stored in the electric field and that stored in the magnetic field

D.ย differenceย ofย theย averageย energyย storedย inย theย electricย fieldย andย that stored in the magnetic field

Answer: **Option D**

Solution:

319.ย If a series RLC circuit excited by a voltage e = E sin ฯt when LC < 1/ฯ^{2}

A.ย current lags behind the applied voltage

B.ย current leads the applied voltage

C.ย current is in phase with the applied voltage

D.ย voltage across L and C are equal

Answer: **Option B**

Solution:

320.ย The current in the circuit shown is

A.ย 5 A

B.ย 10 A

C.ย 15 A

D.ย 25 A

Answer: **Option A**

Solution:

321.ย In the case of the R-L-C circuit shown in the given figure, the voltage across the R, L and C would be respectively

A.ย 12 V, 16 V and 7 V or 25 V

B.ย 16 V, 12 V and 7 V or 25 V

C.ย 7 V, 16 V and 12 V

D.ย 16 V, 12 V and 25 V

Answer: **Option A**

Solution:

322.ย Consider the following statements regarding the circuit shown in the figure.

If the power consumed by 5 ฮฉ resistor is 10 W then

1.ย |I| = โ2ย A

2.ย the total impedance of the circuit is 5 ฮฉ

3.ย cos ฮธ = 0.866

Which of these statements is correct?

A.ย 1 and 3

B.ย 2 and 3

C.ย 1 and 2

D.ย 1, 2 and 3

Answer: **Option A**

Solution:

323.ย In an ac circuit if voltage V = (a + jb) and current I = (c + jd), then the power is given by

A.ย ac + ad

B.ย ac + bd

C.ย bc – ad

D.ย bc + ad

Answer: **Option B**

Solution:

324.ย The reactive power drawn from the source in the network in the given figure is

A.ย 300 VAR

B.ย 200 VAR

C.ย 100 VAR

D.ย zero

Answer: **Option D**

Solution:

325.ย Aย seriesย R-L-Cย circuit,ย consistingย ofย Rย =ย 10ย ฮฉ,ย X_{L}ย =ย 20ย ฮฉ,ย X_{C}ย =ย 20ย ฮฉย is connectedย acrossย an ac supplyย ofย 100ย Vย (rms).ย Theย magnitudeย andย phase angle (with reference to supply voltage) of the voltage across the inductive coil are respectively

A.ย 100 V, 90ยฐ

B.ย 100 V, -90ยฐ

C.ย 200 V, -90ยฐ

D.ย 200 V, 90ยฐ

Answer: **Option D**

Solution:

326.ย For a capacitor in a sine wave ac circuit

A.ย v_{C} lags i_{C} by 90ยฐ

B.ย i_{C} leads v_{C} by 90ยฐ

C.ย i_{C} and v_{C} have the same frequency

D.ย all of these

Answer: **Option D**

Solution:

327.ย In a series RC circuit,

A.ย V_{C} leads V_{R} by 90ยฐ

B.ย V_{C} and I are in phase

C.ย V_{C} lags V_{R} by 90ยฐ

D.ย both B and C

Answer: **Option C**

Solution:

328.ย In a series RC circuit,

A.ย V_{C} and V_{R} are in phase

B.ย V_{T} and I are always in phase

C.ย V_{R} and I are in phase

D.ย V_{R} leads I by 90ยฐ

Answer: **Option C**

Solution:

329.ย When the frequency of the applied voltage increases in a series RC circuit

A.ย the phase angle, ฮธ_{T}, becomes more negative

B.ย Z_{T} increases

C.ย Z_{T} decreases

D.ย both A and B

Answer: **Option C**

Solution:

330.ย Inductive reactance, X_{L}

A.ย applies only to non-sinusoidal waveforms or dc

B.ย applies only to sine waves

C.ย applies to either sinusoidal or non-sinusoidal waveforms

D.ย is inversely proportional to frequency

Answer: **Option B**

Solution:

331.ย For an inductor in a sine wave ac circuit

A.ย V_{T} leads i_{L} by 90ยฐ

B.ย V_{T} lags i_{L} by 90ยฐ

C.ย V_{T} and i_{L} are in phase

D.ย none of these

Answer: **Option A**

Solution:

332.ย In a series RL circuit,

A.ย V_{T} lags V_{R} by 90ยฐ

B.ย V_{T} leads V_{R} by 90ยฐ

C.ย V_{R} and I are in phase

D.ย both B and C

Answer: **Option D**

Solution:

333.ย In a series RL circuit where X_{L} = R, the phase angle, ฮธ_{Z}, is

A.ย -45ยฐ

B.ย 0ยฐ

C.ย 90ยฐ

D.ย 45ยฐ

Answer: **Option D**

Solution:

In a series RL circuit where the inductive reactance (XL) is equal to the resistance (R), it implies that the phase angle between the voltage and the current is 45 degrees, as the impedance (Z) is purely resistive. Therefore, the correct answer is:

D. 45ยฐ

334.ย In an ac circuit with only series resistances

A.ย V_{T} and I are in phase

B.ย R_{T} =R1 + R2 + R3 + โฆ + etc.

C.ย each voltage drop is in phase with the series current

D.ย all of these

Answer: **Option D**

Solution:

335.ย The unit of apparent power is the

A.ย volt-ampere (VA)

B.ย watt (W)

C.ย volt-ampere-reactive (VAR)

D.ย joule (J)

Answer: **Option A**

Solution:

336.ย In an ac circuit with only series capacitors

A.ย V_{T} leads I by 90ยฐ

B.ย V_{T} lags I by 90ยฐ

C.ย each capacitor voltage drop leads I by 90ยฐ

D.ย both A and C

Answer: **Option B**

Solution:

337.ย The unit of real power is the

A.ย watt (W)

B.ย volt-ampere (VA)

C.ย joule (J)

D.ย volt-ampere-reactive (VAR)

Answer: **Option A**

Solution:

338.ย In a series RLC circuit

A.ย X_{L} and X_{C} are 180ยฐ out of phase

B.ย I_{L} and I_{C} are 180ยฐ out of phase

C.ย X_{L} and X_{C} are 90ยฐ out of phase

D.ย X_{L} and X_{C} are in phase

Answer: **Option A**

Solution:

339.ย The power factor of an ordinary electric bulb is

A.ย zero

B.ย unity

C.ย slightly more than unity

D.ย slightly less than unity

Answer: **Option B**

Solution:

340.ย The power factor of an ac circuit is equal to

A.ย cosine of the phase angle

B.ย sine of the phase angle

C.ย unity for a resistive circuit

D.ย unity for a reactive circuit

Answer: **Option A**

Solution:

341.ย Ifย f(t)ย = sin tย +ย sin โ2ย tย is passing through R =ย 1ย ohm, whatย is theย power dissipated in 1 ohm resistor?

A.ย 1 W

B.ย 2 W

C.ย since f(t) in non-periodic, not possible to find power

D.ย none of these

Answer: **Option A**

Solution:

C.ย PARALLEL CIRCUITS

342.ย EE Board Exam October 1981

Aย circuitย consistsย ofย X_{L} = j5 ohms,ย X_{C} =ย -j5ย ohmsย and R =ย 5 ohmsย all are connected in parallel. Find the equivalent impedance.

A.ย 5.5 ฮฉ

B.ย 5.0 ฮฉ

C.ย 4.8 ฮฉ

D.ย 5.2 ฮฉ

343.ย EE Board Exam October 1985

Given: Z_{1}ย =ย -j2.5 ohms; Z_{2}ย = j4 ohms; Z_{3}ย = 5 ohms; Z_{4ย } = 1 + j5 ohms. If the four impedances are connected in parallel, find the equivalent impedance in ohms.

A.ย 4.1 + j0.72

B.ย 4.3 + j0.45

C.ย 4.2 + j0.35

D.ย 4.0 + j0.97

Answer: **Option A**

Solution:

344.ย EE Board Exam April 1984, April 1987

Three impedances Z_{a} = 3 + j4 ohms, Z_{b} = 4 โย j4 ohmsย and Z_{c} = j3 ohms are connected in parallel. Solve for the pf of the combination.

A.ย 0.653 leading

B.ย 0.554 lagging

C.ย 0.503 leading

D.ย 0.620 lagging

Answer: **Option B**

Solution:

345.ย EE Board Exam October 1993

A pure capacitance of 530.515 x 10^{-6} farad and an inductance of 530.515 x 10^{-4} Henryย areย connectedย in parallelย acrossย an acย powerย source.ย Solveย for the resultant impedance assuming that the frequency is 30 Hz.

A.ย 10 ฮฉ

B.ย infinite

C.ย zero

D.ย undefined

Answer: **Option B**

Solution:

346.ย REE Board Exam March 1998

Aย coilย ofย aย 50-ohmย resistanceย andย of 150 mHย inductanceย is connectedย in parallel with a 50 ฮผF capacitor. What is the power factor of the circuit?

A.ย 80%

B.ย 50%

C.ย 70%

D.ย 60%

347.ย EE Board Exam April 1982

Three impedances Za, Zb and Zc are connected in parallel. If at 60 Hz, Z_{a} = j8, Z_{b} = -j2 and Z_{c} = 5 ohms. Solve for the resultant power factor.

A.ย 0.471 lagging

B.ย 0.471 leading

C.ย 0.573 lagging

D.ย 0.573 leading

Answer: **Option B**

Solution:

348.ย REE Board Exam October 1997

A resistor of 50 ohms and an impedance of 100 + j50 ohms are connected in parallel across a 220 volts supply. What is the power factor of the load?

A.ย 96%

B.ย 99%

C.ย 98%

D.ย 95%

349.ย EE Board Exam October 1992

A capacitor of 3.18 microfarads is connected in parallel with a resistance of 2,000ย ohms.ย Theย combinationย isย furtherย connectedย inย seriesย withย an inductance of 795 mH andย resistance of 100 ohms across a supply given by e = 400 sin wt + 80 sin (3wt + 60ยฐ). Assume w = 314 radians/sec. Determine the power dissipated.

A.ย 74.66 W

B.ย 78.05 W

C.ย 80.28 W

D.ย 75.66 W

Answer: **Option A**

Solution:

350.ย EE Board Exam October 1992

A capacitor of 3.18 microfarads isย connected in parallel with a resistance of 2,000ย ohms.ย Theย combinationย isย furtherย connectedย inย seriesย withย an inductance of 795 mH and resistance of 100 ohms across a supply given by e = 400 sin wt + 80 sin (3wt + 60ยฐ). Assume w = 314 radians/sec. Determine the circuit power factor.

A.ย 0.702

B.ย 0.650

C.ย 0.633

D.ย 0.612

Answer: **Option B**

Solution:

โ MCQ in AC Circuits Part 8 | REE Board Exam

#### Questions and Answers in AC Circuits

Following is the list of practice exam test questions in this brand new series:

**MCQ in AC Circuits**

**MCQ from Number 1 โ 50**Answer key:

**included**

**MCQ from Number 51 โ 100**Answer key:

**included**

**MCQ from Number 101 โ 150**Answer key:

**included**

**MCQ from Number 151 โ 200**Answer key:

**included**

**MCQ from Number 201 โ 250**Answer key:

**included**

**MCQ from Number 251 โ 300**Answer key:

**included**

**MCQ from Number 301 โ 350**Answer key:

**included**

**MCQ from Number 351 โ 400**Answer key:

**included**

**MCQ from Number 401 โ 450**Answer key:

**included**

**MCQ from Number 451 โ 500**Answer key:

**included**

**MCQ in AC Circuits Series**

P inoyBIX educates thousands of reviewers and students a day in preparation for their board examinations. Also provides professionals with materials for their lectures and practice exams. Help me go forward with the same spirit.

โWill you subscribe today via YOUTUBE?โ

**What You Also Get: FREE ACCESS & DOWNLOAD via GDRIVE**

## TIRED OF ADS?

- Become Premium Member and experienced fewer ads to ads-free browsing.
- Full Content Access Exclusive to Premium members
- Access to PINOYBIX FREEBIES folder
- Download Reviewers and Learning Materials Free
- Download Content: You can see download/print button at the bottom of each post.

## PINOYBIX FREEBIES FOR PREMIUM MEMBERSHIP:

- CIVIL ENGINEERING REVIEWER
- CIVIL SERVICE EXAM REVIEWER
- CRIMINOLOGY REVIEWER
- ELECTRONICS ENGINEERING REVIEWER (ECE/ECT)
- ELECTRICAL ENGINEERING & RME REVIEWER
- FIRE OFFICER EXAMINATION REVIEWER
- LET REVIEWER
- MASTER PLUMBER REVIEWER
- MECHANICAL ENGINEERING REVIEWER
- NAPOLCOM REVIEWER
- Additional upload reviewers and learning materials are also FREE

## FOR A LIMITED TIME

If you subscribe for PREMIUM today!

You will receive an additional **1 month of Premium Membership** FREE.

For **Bronze Membership** an additional **2 months of Premium Membership** FREE.

For **Silver Membership** an additional **3 months of Premium Membership** FREE.

For **Gold Membership** an additional **5 months of Premium Membership** FREE.

Join the PinoyBIX community.