71 + Interview Questions in Magnetic Forces And Materials in Electromagnetic Theory Page 2 InterviewSolution

51.	Find the torque of a loop with magnetic moment 12.5 and magnetic flux density 7.65 units is(a) 95.625(b) 65.925(c) 56.525(d) 65.235I had been asked this question in semester exam.This intriguing question originated from Magnetic Dipole in chapter Magnetic Forces and Materials of Electromagnetic Theory
Answer» Right choice is (a) 95.625 Explanation: The TORQUE is DEFINED as the product of the magnetic MOMENT and the magnetic flux DENSITY given by T = MB, where M = 12.5 and B = 7.65. Thus we get T = 12.5 X 7.65 = 95.625 units.

Discussion

52.	The magnetization is defined by the ratio of(a) Magnetic moment to area(b) Magnetic moment to volume(c) Magnetic flux density to area(d) Magnetic flux density to volumeI had been asked this question during an interview for a job.My enquiry is from Magnetic Dipole topic in chapter Magnetic Forces and Materials of Electromagnetic Theory
Answer» Correct CHOICE is (B) Magnetic moment to volume Easiest explanation: The magnetization refers to the AMOUNT of dipole formation in a given volume when it is subjected to a magnetic field. It is given by the RATIO of the magnetic moment to the volume. Thus PM = M/V.

Discussion

53.	The magnetic moment of a field with current 12A and area 1.6 units is(a) 19.2(b) 12.9(c) 21.9(d) 91.2This question was posed to me during a job interview.I'm obligated to ask this question of Magnetic Dipole in chapter Magnetic Forces and Materials of Electromagnetic Theory
Answer» RIGHT option is (a) 19.2 To explain: The magnetic MOMENT is the product of current and the area of the CONDUCTOR. It is given by M = IA, where I = 12 and A = 1.6.Thus we GET, M = 12 x 1.6 = 19.2 units.

Discussion

54.	The magnetic moment and torque are related as follows(a) T = BM(b) B = TM(c) M = TB(d) T = MI had been asked this question during a job interview.I would like to ask this question from Magnetic Torque in section Magnetic Forces and Materials of Electromagnetic Theory
Answer» Right ANSWER is (a) T = BM Explanation: The TORQUE is defined as the PRODUCT of the magnetic flux density and the magnetic moment. It is given by T = BM, where M = IA is the magnetic moment.

Discussion

55.	Find the angle at which the torque is minimum.(a) 30(b) 45(c) 60(d) 90This question was posed to me during an online exam.I'm obligated to ask this question of Magnetic Torque topic in division Magnetic Forces and Materials of Electromagnetic Theory
Answer» Right CHOICE is (d) 90 Explanation: The torque of a conductor LOOP is given by T = BIA cos θ. The torque is minimum refers to ZERO torque. This is possible only when the angle is 90 or PERPENDICULAR.

Discussion

56.	The torque of a conductor is defined only in the case when(a) The field is perpendicular to the loop(b) The plane of the loop is parallel to the field(c) The plane of the loop is perpendicular to the current direction(d) The field and the current direction are sameI have been asked this question in exam.Origin of the question is Magnetic Torque topic in portion Magnetic Forces and Materials of Electromagnetic Theory
Answer»

Discussion

57.	Consider the conductor to be a coil of turns 60 and the flux density to be 13.5 units, current 0.12A and area 16units. The torque will be(a) 1555.2(b) 1222.5(c) 525.1(d) 255.6I got this question in homework.Question is taken from Magnetic Torque topic in division Magnetic Forces and Materials of Electromagnetic Theory
Answer» The correct option is (a) 1555.2 Explanation: For a single turn or LOOP, the torque will be BIA. For N turns, the torque will be T = NBIA, where N = 60, B = 13.5, I = 0.12 and A = 16. THUS T = 60 X 13.5 x 0.12 x 16 = 1555.2 UNITS.

Discussion

58.	The torque on a conductor with flux density 23 units, current 1.6A and area 6.75 units will be(a) 248.4(b) 192.6(c) 175.4(d) 256.9I got this question by my school teacher while I was bunking the class.My query is from Magnetic Torque topic in portion Magnetic Forces and Materials of Electromagnetic Theory
Answer» Right option is (a) 248.4 To explain: The MAXIMUM TORQUE on a conductor will be at PERPENDICULAR angle ie, at 90. The torque will be given as T = BIA, where B = 23, I = 1.6 and A = 6.75.Thus we get, T = 23 x 1.6 x 6.75 = 248.4 units.

Discussion

59.	Find the torque in a conductor having current 2A, flux density 50 units, length 15cm and distance of 8m.(a) 120(b) 240(c) 800(d) 350I had been asked this question in an international level competition.I want to ask this question from Magnetic Torque in chapter Magnetic Forces and Materials of Electromagnetic Theory
Answer»

Discussion

60.	The distance of the conductor when the area and length of the conductor is 24m2 and 13.56m.(a) 1.76(b) 2.67(c) 1.52(d) 2.15The question was asked in an online quiz.This interesting question is from Magnetic Torque topic in section Magnetic Forces and Materials of Electromagnetic Theory
Answer» Right option is (a) 1.76 Explanation: We know that the surface INTEGRAL is the area component which is the PRODUCT of TWO DIMENSIONS given by length and distance in a CONDUCTOR. Thus A = L x d. To get d, d = A/L = 24/13.56 = 1.76 units.

Discussion

61.	In an field having a force of 12N and distance 20cm, the torque will be(a) 0.24(b) 2.4(c) 24(d) 12/20I had been asked this question by my school principal while I was bunking the class.My question comes from Magnetic Torque topic in chapter Magnetic Forces and Materials of Electromagnetic Theory
Answer» RIGHT choice is (b) 2.4 The best I can explain: The torque is defined as the PRODUCT of the FORCE and distance in a field. THUS T = F x d = 12 x 0.2 = 2.4 units.

Discussion

62.	Find the force that exists in an electromagnetic wave.(a) Electrostatic force(b) Magnetostatic force(c) Lorentz force(d) Electromotive forceI had been asked this question in an online quiz.Question is from Magnetic Torque topic in section Magnetic Forces and Materials of Electromagnetic Theory
Answer» The correct choice is (C) Lorentz force The best explanation: In an electromagnetic WAVE, the force of the electric and magnetic field both coexist. This is GIVEN by F = qE + q(v x B). It is CALLED Lorentz force.

Discussion

63.	Find the maximum force of the conductor having length 60cm, current 2.75A and flux density of 9 units.(a) 14.85(b) 18.54(c) 84.25(d) 7.256I had been asked this question in an interview for job.Question is from Magnetic Force and Lorentz Force in division Magnetic Forces and Materials of Electromagnetic Theory
Answer» The CORRECT option is (a) 14.85 To ELABORATE: The force on a conductor is GIVEN by F = BIL SIN θ, where B = 3.75, I = 8, L = 0.12 and θ = 90 for maximum force. We get F = BIL= 9 x 2.75 x 0.6 sin 90 = 14.85 units.

Discussion

64.	Find the flux density due to a conductor of length 6m and carrying a current of 3A(in 10^-7 order)(a) 1(b) 10(c) 100(d) 0.1The question was posed to me in unit test.I want to ask this question from Magnetic Force and Lorentz Force in portion Magnetic Forces and Materials of Electromagnetic Theory
Answer» Right CHOICE is (a) 1 The best I can EXPLAIN: The flux density is B = μH, where H = I/2πR. Put I = 3 and R = 6, we get B = 4π X 10^-7 x 3/2π x 6 = 1 x 10^-7 units.

Discussion

65.	When currents are moving in the same direction in two conductors, then the force will be(a) Attractive(b) Repulsive(c) Retracting(d) OpposingI got this question in examination.This intriguing question comes from Magnetic Force and Lorentz Force topic in section Magnetic Forces and Materials of Electromagnetic Theory
Answer» The CORRECT option is (a) Attractive The best I can explain: When two conductors are having currents moving in the same DIRECTION then the FORCES of the two conductors will be moving TOWARDS each other or attractive.

Discussion

66.	The force per unit length of two conductors carrying equal currents of 5A separated by a distance of 20cm in air(in 10^-6 order)(a) 25(b) 35(c) 40(d) 50I got this question during an online exam.This intriguing question comes from Magnetic Force and Lorentz Force in division Magnetic Forces and Materials of Electromagnetic Theory
Answer» Right CHOICE is (a) 25 The best explanation: The force per unit length of TWO CONDUCTORS is GIVEN by F = μ I1xI2/2πD, where I1 = I2 = 5 and D = 0.2. Thus F = 4π x 10^-7 x 52/ 2π x 0.2 = 25 x 10^-6 units.

Discussion

67.	The force on a conductor of length 12cm having current 8A and flux density 3.75 units at an angle of 300 is(a) 1.6(b) 2(c) 1.4(d) 1.8I had been asked this question at a job interview.Asked question is from Magnetic Force and Lorentz Force in portion Magnetic Forces and Materials of Electromagnetic Theory
Answer» The correct option is (d) 1.8 To explain I would say: The force on a conductor is GIVEN by F = BIL sin θ, where B = 3.75, I = 8, L = 0.12 and θ = 300. We get F = 3.75 x 8 x 0.12 sin 30 = 1.8 UNITS.

Discussion

68.	Find the Lorentz force of a charge 2.5C having an electric field of 5 units and magnetic field of 7.25 units with a velocity 1.5m/s.(a) 39.68(b) 68.39(c) 86.93(d) 93.68I got this question by my college director while I was bunking the class.I want to ask this question from Magnetic Force and Lorentz Force in section Magnetic Forces and Materials of Electromagnetic Theory
Answer» Correct option is (a) 39.68 To EXPLAIN I WOULD say: The Lorentz force is GIVEN by F = qE + q(v x B), it is the sum of electric and magnetic force. On substituting q = 2.5, E = 5, v = 1.5 and B = 7.25, F = 2.5(5) + 2.5(1.5 x 7.25) = 39.68 units.

Discussion

69.	Find the electric field when the velocity of the field is 12m/s and the flux density is 8.75 units.(a) 510(b) 105(c) 150(d) 165The question was asked in semester exam.Asked question is from Magnetic Force and Lorentz Force in chapter Magnetic Forces and Materials of Electromagnetic Theory
Answer» Right answer is (b) 105 For explanation: The electric field intensity is the product of the velocity and the magnetic flux density IE, E = V x B = 12 x 8.75 = 105 UNITS.

Discussion

70.	Find the magnetic force when a charge 3.5C with flux density of 4 units is having a velocity of 2m/s.(a) 14(b) 28(c) 7(d) 32This question was posed to me in class test.Enquiry is from Magnetic Force and Lorentz Force topic in division Magnetic Forces and Materials of Electromagnetic Theory
Answer» The correct option is (b) 28 The best I can EXPLAIN: The magnetic force is given by F = q(V X B), where q = 3.5C, v = 2m/s and B = 4 UNITS. Thus we get F = 3.5(2 x 4) = 28 units.

Discussion

71.	Find the electric force when the charge of 2C is subjected to an electric field of 6 units.(a) 6(b) 3(c) 12(d) 24This question was posed to me in a job interview.This interesting question is from Magnetic Force and Lorentz Force in division Magnetic Forces and Materials of Electromagnetic Theory
Answer» The correct answer is (c) 12 The BEST I can EXPLAIN: The electric force is given by F = qE, where q = 2C and E = 6 units. Thus we get F = 2 x 6 = 12 units.

Discussion

Explore topic-wise InterviewSolutions in .

The magnetic moment of a field with current 12A and area 1.6 units is(a) 19.2(b) 12.9(c) 21.9(d) 91.2This question was posed to me during a job interview.I'm obligated to ask this question of Magnetic Dipole in chapter Magnetic Forces and Materials of Electromagnetic Theory

The magnetic moment and torque are related as follows(a) T = BM(b) B = TM(c) M = TB(d) T = MI had been asked this question during a job interview.I would like to ask this question from Magnetic Torque in section Magnetic Forces and Materials of Electromagnetic Theory

Find the angle at which the torque is minimum.(a) 30(b) 45(c) 60(d) 90This question was posed to me during an online exam.I'm obligated to ask this question of Magnetic Torque topic in division Magnetic Forces and Materials of Electromagnetic Theory

The distance of the conductor when the area and length of the conductor is 24m2 and 13.56m.(a) 1.76(b) 2.67(c) 1.52(d) 2.15The question was asked in an online quiz.This interesting question is from Magnetic Torque topic in section Magnetic Forces and Materials of Electromagnetic Theory

In an field having a force of 12N and distance 20cm, the torque will be(a) 0.24(b) 2.4(c) 24(d) 12/20I had been asked this question by my school principal while I was bunking the class.My question comes from Magnetic Torque topic in chapter Magnetic Forces and Materials of Electromagnetic Theory

Find the force that exists in an electromagnetic wave.(a) Electrostatic force(b) Magnetostatic force(c) Lorentz force(d) Electromotive forceI had been asked this question in an online quiz.Question is from Magnetic Torque topic in section Magnetic Forces and Materials of Electromagnetic Theory

Find the flux density due to a conductor of length 6m and carrying a current of 3A(in 10^-7 order)(a) 1(b) 10(c) 100(d) 0.1The question was posed to me in unit test.I want to ask this question from Magnetic Force and Lorentz Force in portion Magnetic Forces and Materials of Electromagnetic Theory

Find the electric field when the velocity of the field is 12m/s and the flux density is 8.75 units.(a) 510(b) 105(c) 150(d) 165The question was asked in semester exam.Asked question is from Magnetic Force and Lorentz Force in chapter Magnetic Forces and Materials of Electromagnetic Theory

Find the magnetic force when a charge 3.5C with flux density of 4 units is having a velocity of 2m/s.(a) 14(b) 28(c) 7(d) 32This question was posed to me in class test.Enquiry is from Magnetic Force and Lorentz Force topic in division Magnetic Forces and Materials of Electromagnetic Theory

Find the electric force when the charge of 2C is subjected to an electric field of 6 units.(a) 6(b) 3(c) 12(d) 24This question was posed to me in a job interview.This interesting question is from Magnetic Force and Lorentz Force in division Magnetic Forces and Materials of Electromagnetic Theory