MCQ in Electricity and Magnetism Fundamentals Part 9 | ECE Board Exam

(Last Updated On: November 25, 2020)

This is the Multiple Choice Questions Part 9 of the Series in Electricity and Magnetism Fundamentals 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 Atomic Structure
• MCQ in Electric Charge
• MCQ in Ohm’s Law, Kirchhoff Law, Coulomb’s Law, etc
• MCQ in Magnetic Power
• MCQ in Magnetic Field and Magnetic Flux
• MCQ in Magnetic and Electric Quantities / Units
• MCQ in Magnetic/Electromagnet Principles

Continue Practice Exam Test Questions Part 9 of the Series

Choose the letter of the best answer in each questions.

401. Where does practically all of the RF current flow in a conductor?

A. along the surface

B. in the center of the conductor

C. in the electromagnetic field in the conductor center

D. in the magnetic field around the conductor

402. ________ is one factor that does not affect resistance.

A. Cross sectional area

B. Resistivity

C. Mass

D. Length

403. Why is the resistance of a conductor different for RF current than for DC?

A. Because of skin effect

B. Because conductors are non-linear devices

C. Because the insulation conducts current at radio frequency

D. Because of the Heisenberg effect

404. The ability of a material to resist current flow is called “resistance”. What is (are) the factor(s) that affect its value?

A. temperature

B. length & cross-sectional area

C. atomic structure

D. all of these

405. Find the charge in coulombs of dielectric that has a positive charge of 14.5 x 10 to the 18th power protons.

A. 29 x 10 to the 16th Coulombs

B. 14.5 x 10 to the 16th Coulombs

C. 14.5 x 10 to the 18th Coulombs

D. 29 x 10 to the 18th Coulombs

406. Electron volt (eV) is a unit of

A. power

B. energy

C. magnetic field

D. magnetic force

407. One electron volt (eV) is equivalent to

A. 1.0 watt-sec

B. 1.6 x 10^-19 watt-sec

C. 1.0 Joule

D. 1.6 x 10^-19 Joules

408. What law that describes the force of attraction or repulsion between two charges is directly proportional to their strengths and inversely proportional to the square of the

distance between them?

A. Coulomb’s first law

B. Coulomb’s second law

C. Coulomb’s third law

D. Coulomb’s law or law of electrostatics

409. What is the law whereby the force of attraction and repulsion between poles is inversely proportional to the square of the distance between them?

A. Newton’s first law

B. Newton’s second law

C. Norton’s law

D. Coulomb’s second law

410. Is usually used to detect the presence of electric charge.

A. experimental charge

B. unit charge

C. dipole

D. test charge

411. Test charge has a charge of

A. 0 Coulomb

B. +1 Coulomb

C. -1 Coulomb

D. Infinity

412. Three charges of +5 C, -6 C and +7 C are placed inside a sphere, what is the total charge of the sphere?

A. +5 Coulomb

B. -6 Coulomb

C. -7 Coulomb

D. +6 Coulomb

413. A combination of two charges, with equal charge magnitude but opposite signs.

A. magnetic dipole

B. static dipole

C. dynamic dipole

D. electric dipole

414. The space outside or surrounding an electric charge where it has a force of attraction or repulsion.

A. Electric field

B. Magnetic field

C. Electromagnetic field

D. Electric flux

415. Refers to a force of field that exists between ions where they either repel or attract each other.

A. Resisting field

B. Potential field

C. Dielectric

D. Electromotive

416. The imaginary lines representing the electric field.

A. Electric field

B. Electric flux

C. Electric flux density

D. Electric lines of force

417. What is true in visualizing electric field lines of force from a charge body?

A. Field lines are continuous curve and they never intersect.

B. The spacing between these lines increases as they get far from the charged body.

C. The number of field lines is directly proportional to the magnitude of the electric field.

D. All of the above.

418. What do you call the total number of electric lines of force in an electric field?

A. Electric field

B. Electric flux

C. Electric flux density

D. Electric lines of force

419. The number of lines per unit area in a plane perpendicular to the electric lines of force.

A. Electric field

B. Electric flux

C. Electric flux density

D. Electric lines of force

420. Electric lines of force leave and enter the charge surface at what angle?

A. 15°

B. 30°

C. 45°

D. 90°

421. Find the dielectric constant of air.

A. approximately 1

B. approximately 0

C. approximately 2

D. approximately 4

422. Electric field intensity is measured in terms of

A. Volts/meter

B. Newtons/meter

C. Watts/meter

D. Amperes/meter

423. Electric field intensity is

A. a scalar quantity

B. a vector quantity

C. an absolute value

D. a relative value

424. Electric flux is a/an ________ quantity.

A. scalar

B. vector

C. absolute

D. relative

425. Electric flux density is a/an ________ quantity.

A. scalar

B. vector

C. absolute

D. relative

426. Three charges of +5 C, -6 C, and +7 C are inside a sphere, what is the total electric flux passing through the surface of the sphere?

A. 5 Coulombs

B. 6 Coulombs

C. 7 Coulombs

D. 8 Coulombs

427. An electric charge produces a total electric field of 6 Coulombs, calculate the electric flux density in an area of one square meter (1m2).

A. 1 C/m^2

B. 2 C/m^2

C. 4 C/m^2

D. 6 C/m^2

428. The measure of density of the electric charge

A. Electric gradient

B. Electric current

C. Electric charge

D. Electric potential

429. The ability of the material to store electrical potential energy under the influence of an electric field.

A. capacity

B. permeability

C. permittivity

D. conductivity

430. The absolute permittivity of air or free space.

A. 1/36π x 10^-9 F/m

B. 36π x 10^-9 F/m

C. 1/36π x 10^-19 F/m

D. 36π x 10^-19 F/m

431. The relative permittivity of air.

A. 0

B. 1

C. 1/36π x 10^-9 F/m

D. 8.854 x 10^-12 F/m

432. Calculate the permittivity of a material with relative permittivity of 5.

A. 8.854 x 10^-11 F/m

B. 4.42 x 10^-11 F/m

C. 1/36π x 10^-9 F/m

D. 8.854 x 10^-12 F/m

433. What is the term used to express the amount of electrical energy stored in an electrostatic field?

A. Volts

B. Watts

C. Coulombs

D. Joules

434. How does permittivity affect electric field intensity?

A. It causes the field intensity to increase.

B. It causes the field intensity to decrease.

C. It causes the field intensity to fluctuate up and down.

D. It has no effect on field intensity.

435. Relative permittivity is also known as

A. dielectric constant

B. dielectric strength

C. isolation strength

D. permeability

436. Most materials’ relative permittivity lies between

A. 0.01 – 1

B. 1 – 10

C. 10 – 50

D. 50 – 100

437. Charge body at rest is said to exhibit electric field, which interacts with other bodies. The study of this phenomena is known as

A. electricity

B. electrostatics

C. electromagnetism

D. field interactions

438. The basic law for interaction of charged bodies at rest.

A. Charged law

B. Gauss’ law

C. Faraday’s law

D. Coulomb’s law

439. The force between the two electrically charged body is called

A. electromotive force

B. electrostatic force

C. electromagnetic force

D. magnetic force

440. The force between two electrically charged body is

A. directly proportional to the charge

B. inversely proportional to the charge

C. not affected by the charge

D. universally constant

441. In 1784, who demonstrated that the force between charges is inversely related to the square of the distance between them?

A. Maxwell

B. Gauss

C. Tesla

D. Coulomb

442. Determine the force in Newton between 4μC charges separated by 0.1 meter in air.

A. 1.44 N

B. 14.4 N

C. 144 N

D. 1440 N

443. What will happen when two opposite charges get closer?

A. repels less

B. attracts less

C. repels more

D. attracts more

444. The value of k in Coulomb’s electrostatic force equation ( F = kQ1Q2/r^2 ) is oftentimes expressed as 1/4πεο. What is εο?

A. absolute permeability

B. absolute permittivity

C. relative permeability

D. relative permittivity

445. The measure of electric field strength per unit length is known as electric field intensity or simply electric intensity. What is its unit?

A. Volt/meter (V/m)

B. Joules/Coulomb-meter (J/Cm)

C. Newton/Coulomb (N/C)

D. All of the above

446. Calculate the electric field intensity 10cm from a charge Q = 5nC.

A. 450 N/C

B. 900 N/C

C. 4.5 x 10^3 N/C

D. 9.0 x 10^3 N/C

447. Determine the magnitude of the electric field inside a sphere that encloses a net charge of 2 μC.

A. 0 (zero)

B. 9 x 10^7 N/C

C. 1.8 x 10^8 N/C

D. infinite

448. Calculate the total electric field at the surface of a sphere of radius r = 1cm, and enclosing a net charge of 2 μC.

A. 0 (zero)

B. 9 x 10^7 N/C

C. 1.8 x 10^8 N/C

D. infinite

449. A 2nC point charge will produce what potential at 2 m away?

A. 4.0 Volts

B. 6.0 Volts

C. 7.5 Volts

D. 9.0 Volts

450. A charged body in free space produces 10-V potential at a distance 25 cm away. What will be the potential at 50 cm away?

A. 5.0 Volts

B. 7.5 Volts

C. 10.0 Volts

D. 15.0 Volts

Questions and Answers in Electricity and Magnetism Fundamentals

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