# MCQ in Electrical Circuit Part 8 | ECE Board Exam

(Last Updated On: November 24, 2020) This is the Multiples Choice Questions Part 8 of the Series in Electrical Circuit as one of the Electronics Engineering topic. In Preparation for the ECE 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 Electronics Engineering field, Electronics Books, Journals and other Electronics References.

#### MCQ Topic Outline included in ECE Board Exam Syllabi

• MCQ in AC-DC circuits
• MCQ in Resistors
• MCQ in Inductors
• MCQ in Capacitors

#### Continue Practice Exam Test Questions Part 8 of the Series

Choose the letter of the best answer in each questions.

351. The return point in a circuit, where all voltage measurements are referred.

A. node

B. junction

C. ground

D. loop

View Answer:

Answer: Option C

Solution:

352. Mesh analysis is best used together with what circuit law?

A. KVL

B. KCL

C. VDT

D. CDT

View Answer:

Answer: Option A

Solution:

353. Nodal analysis is best used together with

A. KVL

B. KCL

C. VDT

D. CDT

View Answer:

Answer: Option B

Solution:

354. Three 100 Ω resistors are connected in a tee-form (T) network and is set up between a 100 V supply and a load resistor RL. If maximum power transfer is desired, what should be the resistance of the load resistor RL?

A. 50 Ω

B. 75 Ω

C. 125 Ω

D. 150 Ω

View Answer:

Answer: Option D

Solution:

355. Theorem used in simplifying circuit analysis by considering the effect of supply voltages one at a time.

A. Thevenin’s theorem

B. Norton’s theorem

C. Superposition

D. KVL

View Answer:

Answer: Option C

Solution:

356. Three resistors, R1 = 60 Ω, R2 = 80 Ω and R3 = 100 are connected in delta. If the network is to be transformed into star, what would be the value of the resistor opposite of R2?

A. 25.0 Ω

B. 33.3 Ω

C. 45.0 Ω

D. 56.7 Ω

View Answer:

Answer: Option A

Solution:

357. The description of two sine waves that are in step with each other going through their maximum and minimum points at the same time and in the same direction

A. phased sine wave

B. sine waves in phase

C. sine wave in coordination

D. stepped sine waves

View Answer:

Answer: Option B

Solution:

358. Most ac-supplies are in the form of

A. sine-wave

B. square-wave

C. triangular-wave

D. rectangular-wave

View Answer:

Answer: Option A

Solution:

359. Advantage(s) of ac over dc

A. economically produced

B. transmission of ac is more efficient

C. ac voltages can be easily changed

D. all of the above

View Answer:

Answer: Option D

Solution:

360. An ac-voltage has an equation v = 240 sin120πt, its frequency is

A. 60 Hz

B. 90 Hz

C. 120 Hz

D. 240 Hz

View Answer:

Answer: Option A

Solution:

361. When can an ac-voltage, v = 120sin120πt reach its first peak?

A. 4.167 μs

B. 8.334 μs

C. 4.167 ms

D. 8.334 ms

View Answer:

Answer: Option C

Solution:

362. Calculate the period of an alternating current having an equation of I = 20sin120πt.

A. 4.167 ms

B. 8.33 ms

C. 16.67 ms

D. 33.33 ms

View Answer:

Answer: Option C

Solution:

363. The time taken by an alternating voltage, v = 100sin240πt to reach 50V for the first time

A. 358 μs

B. 695 μs

C. 358 ms

D. 695 ms

View Answer:

Answer: Option D

Solution:

364. An alternating voltage of sine-wave form has a maximum voltage of 311V. What is its value at 225°?

A. 110 V

B. 220 V

C. -220 V

D. -110 V

View Answer:

Answer: Option C

Solution:

365. If an alternating voltage has a magnitude of 10 V at 30°, what is its maximum voltage?

A. 20 V

B. 30 V

C. 40 V

D. 50 V

View Answer:

Answer: Option A

Solution:

366. What is the frequency of an alternating current, if it reaches 90° within 4.167 ms?

A. 20 Hz

B. 30 Hz

C. 50 HZ

D. 60 Hz

View Answer:

Answer: Option C

Solution:

367. At what angle does an alternating voltage of cosine-waveform reaches its negative peak?

A. 45°

B. 90°

C. 135°

D. 180°

View Answer:

Answer: Option D

Solution:

368. When comparing rms voltages and average voltages, which of the following statement is true, assuming sine waves?

A. Either the rms voltage or the average voltage might be larger

B. The rms voltage is always greater than the average voltage

C. There will always be a very large difference between the rms voltage and the average voltage

D. The average voltage is always greater than the rms voltage

View Answer:

Answer: Option B

Solution:

369. What is the average voltage of an alternating voltage, v = 100sin120πt?

A. 31.8 V

B. 63.6 V

C. 70.71 V

D. 0 (zero) V

View Answer:

Answer: Option D

Solution:

370. Determine the effective voltage of v = 100sin120πt.

A. 31.80 V

B. 35.35 V

C. 70.71 V

D. 90.00 V

View Answer:

Answer: Option D

Solution:

371. What do you mean by root-mean-squared (rms) value?

A. it is the average value

B. it is the effective value

C. it is the value that causes the same heating effect as a dc-voltage

D. B or C

View Answer:

Answer: Option D

Solution:

372. The power dissipated across the resistance in an AC circuit

A. real power

B. reactive power

C. apparent power

D. true power

View Answer:

Answer: Option D

Solution:

373. In AC circuit, resistors will dissipate what power?

A. reactive

B. passive

C. inductive

D. true

View Answer:

Answer: Option D

Solution:

374. In an ac-circuit, if the voltage and current are in phase, the circuit is

A. resistive

B. reactive

C. capacitive

D. inductive

View Answer:

Answer: Option A

Solution:

375. If the current in an ac-circuit leads the voltage by 90°, the circuit is

A. resistive

B. capacitive

C. inductive

D. purely inductive

View Answer:

Answer: Option B

Solution:

376. In a purely inductive circuit the current

A. leads the voltage by 45°

B. leads the voltage by 90°

C. lags the voltage by 90°

D. lags the voltage by 45°

View Answer:

Answer: Option C

Solution:

377. If the current and voltage in an ac-circuit has a phase difference, it would mean the load is

A. resistive

B. capacitive

C. inductive

D. reactive

View Answer:

Answer: Option D

Solution:

378. A resistive and a capacitive load of equal magnitude is connected in series, determine the phase difference between the voltage and the current.

A. current leads the voltage by 45°

B. current lags the voltage by 45°

C. current leads the voltage by 90°

D. current lags the voltage by 90°

View Answer:

Answer: Option A

Solution:

379. The reactance of a 25 mH coil at 500 Hz is which of the following?

A. 785 ohms

B. 785,000 ohms

C. 13 ohms

D. 0.0013 ohms

View Answer:

Answer: Option A

Solution:

380. The impedance in the study of electronics is represented by resistance and ________.

A. inductance and capacitance

B. inductance

C. reactance

D. capacitance

View Answer:

Answer: Option C

Solution:

381. A series circuit consists of an 80 mH inductor and a 150 μF capacitor. Calculate the total reactance if it is connected to a 220-volt 60-cycle source.

A. 12.5 Ω inductive

B. 12.5 Ω capacitive

C. 47.8 Ω inductive

D. 47.8 Ω capacitive

View Answer:

Answer: Option A

Solution:

382. Ignoring any inductive effects, what is the impedance of RC series capacitor made up of a 56 kilo ohms resistor and a 0.33 μF capacitor at a signal frequency of 450 Hz?

A. 66,730 ohms

B. 57,019 ohms

C. 45,270 ohms

D. 10,730 ohms

View Answer:

Answer: Option B

Solution:

383. A 220-volt, 60-Hz source is driving a series RL circuit. Determine the current in the circuit if R = 100 Ω and XL = 100 Ω.

A. 1.10 A (lagging)

B. 1.55 A (lagging)

C. 2.20 A (lagging)

D. 4.40 A (lagging)

View Answer:

Answer: Option B

Solution:

384. How many electrical degrees a current will lead the voltage in a series RC load with R = 100 Ω and XC = 50 Ω?

A. 13.28°

B. 26.56°

C. 31.72°

D. 63.44°

View Answer:

Answer: Option B

Solution:

385. What will be the current equation in a series RC network if supplied with v = Vmsin120πt source. The circuit has a power factor pf = 0.5?

A. i = Imaxsin(120πt + 60)

B. i = Imaxsin(120πt – 60)

C. i = Imaxsin(120πt + 30)

D. i = Imaxsin(120πt – 30)

View Answer:

Answer: Option A

Solution:

386. The power factor (pf) of a series LC circuit is

A. 0

B. 0.5

C. 0.75

D. 1.0

View Answer:

Answer: Option A

Solution:

387. What is the power factor (pf) of a series RL circuit having R = 50Ω and XL = 20Ω?

A. 0.63

B. 0.71

C. 0.81

D. 0.93

View Answer:

Answer: Option D

Solution:

388. A 200Ω resistor if connected in series with a capacitive reactance of 100 will give a total circuit impedance of

A. 173.2 Ω

B. 223.6 Ω

C. 250.6 Ω

D. 300.0 Ω

View Answer:

Answer: Option B

Solution:

389. What will happen when the power factor of a circuit is increased?

A. reactive power increases

B. active power increases

C. both active and reactive powers increases

D. both active and reactive powers decreases

View Answer:

Answer: Option B

Solution:

390. A series RL network is supplied with a 200-volt, 60-cycle source. If the voltage across the resistor R is 100 V, what is the voltage across the inductor L?

A. 0 V

B. 100 V

C. 173.2 V

D. 200 V

View Answer:

Answer: Option C

Solution:

391. A 6-Ω resistor is connected in series with a capacitive reactance of 8 Ω. If the supply voltage is 200 V, what is the power consumed by the circuit?

A. 2400 W

B. 4000 W

C. 5000 W

D. 6666.67 W

View Answer:

Answer: Option A

Solution:

392. A 6-Ω resistor is connected in series with a capacitive reactance of 8 Ω. If the supply voltage is 200 V, what is the circuit current magnitude?

A. 14.28 A

B. 20 A

C. 25 A

D. 33.33 A

View Answer:

Answer: Option B

Solution:

393. A 6-Ω resistor is connected in series with a capacitive reactance of 8 Ω. If the supply voltage is 200 V, what is the apparent power of the circuit?

A. 1200 W

B. 2400 W

C. 3200 W

D. 4000 W

View Answer:

Answer: Option D

Solution:

394. The apparent power of a series RC network is given to be 4000 W. If R = 6 Ω, and XC = 8 Ω, calculate the true power of the network.

A. 1200 W

B. 2400 W

C. 3200 W

D. 4000 W

View Answer:

Answer: Option B

Solution:

395. A series RC circuit has an apparent power of 4000 W. If R = 6 Ω, and XC = 8 Ω, determine the reactive power.

A. 1200 W

B. 2400 W

C. 3200 W

D. 4000 W

View Answer:

Answer: Option C

Solution:

396. A network has a true power and a reactive power of 2400 W and 3200 W respectively. What is its apparent power?

A. 800 W

B. 1600 W

C. 4000 W

D. 5600 W

View Answer:

Answer: Option C

Solution:

397. What is the total impedance of a series circuit consisting of R = 6 Ω, XC = 8 Ω, and XL = 16 Ω?

A. 10 Ω

B. 14 Ω

C. 24.73 Ω

D. 30 Ω

View Answer:

Answer: Option A

Solution:

398. What is the significance of connecting loads in parallel?

A. it makes power consumption less

B. it provides greater efficiency

C. it increases the safety factor

D. it allows independent operations of loads

View Answer:

Answer: Option D

Solution:

399. A parallel RL circuit with R = 60 Ω, and XL = 40 Ω has a total impedance of

A. 24.3 Ω

B. 28.3 Ω

C. 33.3 Ω

D. 38.3 Ω

View Answer:

Answer: Option C

Solution:

400. Calculate the total impedance of a parallel RC circuit if R = XC = 50 Ω.

A. 25 @ 45° Ω

B. 25 @ -45° Ω

C. 35.35 @ 45° Ω

D. 35.35 @ -45° Ω

View Answer:

Answer: Option D

Solution:

#### Questions and Answers in Electrical Circuit

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

MCQ in Electrical Circuit
PART 1: MCQ from Number 1 – 50                        Answer key: PART 1
PART 2: MCQ from Number 51 – 100                   Answer key: PART 2
PART 3: MCQ from Number 101 – 150                 Answer key: PART 3
PART 4: MCQ from Number 151 – 200                 Answer key: PART 4
PART 5: MCQ from Number 201 – 250                 Answer key: PART 5
PART 6: MCQ from Number 251 – 300                 Answer key: PART 6
PART 7: MCQ from Number 301 – 350                 Answer key: included
PART 8: MCQ from Number 351 – 400                 Answer key: included
PART 9: MCQ from Number 401 – 450                 Answer key: included
PART 10: MCQ from Number 451 – 500                 Answer key: included

### Complete List of MCQ in Electronics Engineering per topic

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