Directions: The following items consist of two statements, one labeled as “Assertion(A)” and the other labeled as “Reason(R)”. You are to examine the two statements carefully and decide if the Assertion(A) and the Reason(R) are individually true and if so whether the reason is a correct explanation of the assertion. Select your answer to these items using the codes given below and mark your answer accordingly.Assertion (A): The magnetic flux per unit length through a loop of small length is called the magnetic flux density.Reason (R): The direction of magnetic flux density is taken as the normal to the plane of the loop when oriented to enclose maximum flux.

Both (A) and (R) are true and (R) is the correct explanation of (A).

Both (A) and (R) are true, but (R) is not the correct explanation of (A).

"In all cases electromagnetic induction, an induced voltage will cause a current to flow in a closed circuit in such a direction that the magnetic field which is caused by that current will oppose the change that produces the current", is the original statement of _____.

Faraday's law of magnetic induction

A long solenoid of radius R, having N turns per unit length carries a time depend current I(t) = I0 sin (ωt). The magnitude of induced electric field at a distance R/2 radially from the axis of the solenoid is

\(\frac{R}{2}{\mu _0}N\;{I_0}\;\omega \sin \left( {\omega t} \right)\)

\(\frac{R}{2}{\mu _0}N\;{I_0}\;\omega \cos \left( {\omega t} \right)\)

\(\frac{R}{4}{\mu _0}N\;{I_0}\;\omega \cos \left( {\omega t} \right)\)

\(\frac{R}{2}{\mu _0}N\;{I_0}\;\omega \sin \left( {\omega t} \right)\)

\(\frac{R}{4}{\mu _0}N\;{I_0}\;\omega \sin \left( {\omega t} \right)\)

A coil wound over an iron carries a certain current and establishes flux in the ring. If the area of a cross-section of the ring is doubled, the flux in the core _____.

is double of the previous value

Directions: It consists of two statements, one labelled as the ‘Statement (I)’ and the other as ‘Statement (II)’. Examine these two statements carefully and select the answers to these items using the codes given below:Statement (I):The magnetic moments of diamagnetic materials are mainly due to the orbital angular momentum of the electrons.Statement (II):A steady current flowing in the orbit produces a magnetic field equivalent to that set up by a dipole perpendicular to the plane of orbit (Ampere’s law).

Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)

Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)

Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)

Statement (I) is true but Statement (II) is false

Statement (I) is false but Statement (II) is true

Calculate the value of flux leakage coefficient, if ϕg is the air gap flux and ϕa is the flux in iron core.

\(\frac{{{\phi _g}}}{{{\phi _a}}}\)

\(\frac{{{\phi _a}}}{{{\phi _g}}}\)

A solenoid having N turns and I amperes will have an inductance of ________ henry.

\(\frac{{{\rm{N}}\phi }}{{\rm{I}}}\)

\(\frac{{{\rm{I}}\phi }}{{\rm{N}}}\)

In magnetic circuits, due to fringing effect, the following is true if Bc represents core flux density and Bg represents average air gap flux density.

Bg remains unaffected due to fringing

Magnetostriction is the effect produced when change of magnetization in magnetic material results in

change of magnetic field strength

120 + Mcqs in Magnetostatics in Electromagnetic Theory Page 1 McqOptions

1.	A coil of 500 turns wound on a core of non-magnetic material has an inductance of 20 mH. The average value of the EMF induced when a current of 2 A is reversed in 5 ms is:
A.	8 V
B.	16 V
C.	6 V
D.	24 V
Answer» C. 6 V

Discussion

2.	Hysteresis loss in a transformer is proportional to which of the following quantity?
A.	\(B_{max}\)
B.	\(B_{max}^{1.6}\)
C.	\(B_{max}^{0.6}\)
D.	\(B_{max}^{-0.6}\)
Answer» C. \(B_{max}^{0.6}\)

Discussion

3.	Magnetic field intensity has the dimension
A.	IL
B.	I2L
C.	IL-1
D.	IL-2
Answer» D. IL-2

Discussion

4.	A long straight wire carries a current I = 10 A. At what distance is the magnetic field H = 1 A/m?
A.	10/2π
B.	½ π
C.	5/2π
D.	20/2π
Answer» B. ½ π

Discussion

5.	Directions: The following items consist of two statements, one labeled as “Assertion(A)” and the other labeled as “Reason(R)”. You are to examine the two statements carefully and decide if the Assertion(A) and the Reason(R) are individually true and if so whether the reason is a correct explanation of the assertion. Select your answer to these items using the codes given below and mark your answer accordingly.Assertion (A): The magnetic flux per unit length through a loop of small length is called the magnetic flux density.Reason (R): The direction of magnetic flux density is taken as the normal to the plane of the loop when oriented to enclose maximum flux.
A.	Both (A) and (R) are true and (R) is the correct explanation of (A).
B.	Both (A) and (R) are true, but (R) is not the correct explanation of (A).
C.	(A) is true, but (R) is false.
D.	(A) is false, but (R) is true.
Answer» E.

Discussion

6.	Magnetic field intensity (H) of a long conductor carrying current ‘I’ at a distance ‘r’ is _________
A.	\(\frac{I}{{4\pi r}}\)
B.	\(\frac{I}{{2\pi r}}\)
C.	\(\frac{I}{{4r}}\)
D.	\(\frac{I}{{2r}}\)
Answer» C. \(\frac{I}{{4r}}\)

Discussion

7.	"In all cases electromagnetic induction, an induced voltage will cause a current to flow in a closed circuit in such a direction that the magnetic field which is caused by that current will oppose the change that produces the current", is the original statement of _____.
A.	Lenz's law
B.	Faraday's law of magnetic induction
C.	Fleming's law of induction
D.	Ampere's law
Answer» B. Faraday's law of magnetic induction

Discussion

8.	A conductor of length 100 cm moves at right angle to a uniform field flux density of 1.5 Wb/m2 with a velocity of 50 m/s. The e.m.f. induced in the conductor will be
A.	150 V
B.	75 V
C.	50 V
D.	37.5 V
Answer» C. 50 V

Discussion

9.	A 25 μC point charge is located at origin. Calculate electric flux passing through the portion of sphere defined by r = 20 cm, bounded by θ = 0 and π rad, ϕ = 0 and π/2 rad.
A.	5 μC
B.	25 μC
C.	6.25 μC
D.	12.5 μC
Answer» D. 12.5 μC

Discussion

10.	A solenoid has 4000 turns over it with inductance of 0.126 H. The energy stored in the magnetic field, when a current of 2 A flows in the solenoid will be
A.	0.252 J
B.	8000 J
C.	0.504 J
D.	1008 J
Answer» B. 8000 J

Discussion

11.	A magnetic circuit of reluctance 3000 A-turns/Wb is wounded by a wire of 400 turns. Determine the average emf induced (in V) in the coil, if a current of 2 A is flowing in the coil is reversed in 15 s.
A.	14.24
B.	16.28
C.	17.96
D.	19.62
Answer» B. 16.28

Discussion

12.	In a magnetic tape blanks are provided at the _____.
A.	start of the tape
B.	middle of the tape
C.	end of the tape
D.	start and end of the tape
Answer» E.

Discussion

13.	If a circular conductor carries a current of ‘I’ ampere having radius ‘r’ meter, then the magnetizing force at the center of the coil is given by ;
A.	\(\frac{I}{{4r}}At/m\)
B.	\(\frac{I}{r}At/m\)
C.	\(\frac{I}{{2r}}At/m\)
D.	\(\frac{I}{{2r}}At/Wb\)
Answer» D. \(\frac{I}{{2r}}At/Wb\)

Discussion

14.	Magnetic field intensity (H), within a magnetic material where, M = 150 A/m, μ = 1.5 × 10-5 H/m, μr = 30;
A.	14.921 A/m
B.	14.138 A/m
C.	1.82 A/m
D.	13.715 A/m
Answer» E.

Discussion

15.	A long solenoid of radius R, having N turns per unit length carries a time depend current I(t) = I0 sin (ωt). The magnitude of induced electric field at a distance R/2 radially from the axis of the solenoid is
A.	\(\frac{R}{2}{\mu _0}N\;{I_0}\;\omega \cos \left( {\omega t} \right)\)
B.	\(\frac{R}{4}{\mu _0}N\;{I_0}\;\omega \cos \left( {\omega t} \right)\)
C.	\(\frac{R}{2}{\mu _0}N\;{I_0}\;\omega \sin \left( {\omega t} \right)\)
D.	\(\frac{R}{4}{\mu _0}N\;{I_0}\;\omega \sin \left( {\omega t} \right)\)
Answer» C. \(\frac{R}{2}{\mu _0}N\;{I_0}\;\omega \sin \left( {\omega t} \right)\)

Discussion

16.	Determine the magnetic field strength (in A/m) of a material when the intensity of magnetization of the material is 0.084 Amp/m and the magnetic susceptibility of the material is 0.0012.
A.	70
B.	700
C.	0.7
D.	0.07
Answer» B. 700

Discussion

17.	A coil wound over an iron carries a certain current and establishes flux in the ring. If the area of a cross-section of the ring is doubled, the flux in the core _____.
A.	is double of the previous value
B.	is half of the previous value
C.	is same as the previous value
D.	is not possible to predict
Answer» B. is half of the previous value

Discussion

18.	Permanent Magnets are made of
A.	Diamagnetic Materials
B.	Paramagnetic Materials
C.	Ferromagnetic Materials
D.	Piezoelectric Materials
Answer» D. Piezoelectric Materials

Discussion

19.	A conductor of length 1 m moves at right angles to a uniform magnetic field of flux density 2 Wb/m2 with a velocity of 50 m/s. What is the value of the induced e.m.f., when the conductor moves at an angle of 30° to the direction of the field?
A.	75 V
B.	50 V
C.	25 V
D.	12.5 V
Answer» C. 25 V

Discussion

20.	Magnetic flux density is quantified in terms of ______.
A.	Weber
B.	Lumen
C.	Lux
D.	Tesla
Answer» E.

Discussion

21.	Directions: It consists of two statements, one labelled as the ‘Statement (I)’ and the other as ‘Statement (II)’. Examine these two statements carefully and select the answers to these items using the codes given below:Statement (I):The magnetic moments of diamagnetic materials are mainly due to the orbital angular momentum of the electrons.Statement (II):A steady current flowing in the orbit produces a magnetic field equivalent to that set up by a dipole perpendicular to the plane of orbit (Ampere’s law).
A.	Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)
B.	Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)
C.	Statement (I) is true but Statement (II) is false
D.	Statement (I) is false but Statement (II) is true
Answer» B. Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)

Discussion

22.	Consider the following statements:1. The magnetic field at the centre of the circular coil of a wire carrying current is inversely proportional to the radius of the coil.2. Lifting power of a magnet is proportional to the square of magnetic flux density.3. A static electric field is conservative (rotational)4. If the divergence of a vector 'A' is zero, then that vector can be expressed as Curl of a vector F
A.	1, 2, 3 only
B.	3 and 4 only
C.	1, 2 and 4 only
D.	1, 2, 3 and 4
Answer» E.

Discussion

23.	A current flows in a conductor from east to west. The direction of magnetic fields at a point above the conductor is
A.	toward the north
B.	toward the south
C.	toward the east
D.	toward the west
Answer» B. toward the south

Discussion

24.	Calculate the value of flux leakage coefficient, if ϕg is the air gap flux and ϕa is the flux in iron core.
A.	\(\frac{{{\phi _g}}}{{{\phi _a}}}\)
B.	\(\frac{{{\phi _a}}}{{{\phi _g}}}\)
C.	\({\phi _a}{\phi _g}\)
D.	\({\phi _a} + {\phi _g}\)
Answer» C. \({\phi _a}{\phi _g}\)

Discussion

25.	For magnetic circuits, the relationship which is similar to application of Ohm’s Law is, (where ϕ is flux, S is reluctance)
A.	ϕ = S/mmf
B.	mmf = ϕ/S
C.	ϕ = mmf/S
D.	None of the above
Answer» D. None of the above

Discussion

26.	If l is the length of a conductor lying within the magnetic field and I is the ampere current carried by it, then magnitude of the force experienced by it is:
A.	F = Idl sin θ
B.	F = Il
C.	F = IlB sin θ
D.	F = Il sin θ
Answer» D. F = Il sin θ

Discussion

27.	Consider the following statements regarding hysteresis loops of hard and soft magnetic materials:1. Hysteresis loss of hard magnetic material will be less than that of soft material2. Coercivity of hard material will be greater than that of soft material3. Retentivity of the two materials will always be equalWhich of these statements are correct?
A.	1, 2 and 3
B.	2 only
C.	3 only
D.	1 and 3 only
Answer» C. 3 only

Discussion

28.	Consider the following statements regarding an ideal core material:1. It has very high permeability.2. It loses all its magnetism when there is no current flow.3. It does not saturate easily.Which of the above statements are correct?
A.	1 and 2 only
B.	1 and 3 only
C.	1, 2 and 3
D.	2 and 3 Only
Answer» D. 2 and 3 Only

Discussion

29.	Consider the following statements:1. Fleming’s rule is used where induced E.M.F. is due to flux cutting.2. Lenz’s law is used when the induced E.M.F. is due to a change in flux linkages.3. Lenz’s law is a direct consequence of the law of conservation of energy.Which of the above statements are correct?
A.	1 and 2 only
B.	1 and 3 only
C.	2 and 3 only
D.	1, 2 and 3
Answer» E.

Discussion

30.	Permeance is inversely related to
A.	resistance
B.	conductance
C.	reluctance
D.	capacitance
Answer» D. capacitance

Discussion

31.	Determine the magnetic susceptibility of a material, if the field strength of the material is 0.8 × 105 A – m-1 and the magnitude of magnetization is 0.97 × 105 A – m-1
A.	1.01
B.	1.21
C.	1.41
D.	1.61
Answer» C. 1.41

Discussion

32.	In ferroelectric materials, the hysteresis loop is the __________ function of the applied electric field.
A.	parabolic
B.	non-linear
C.	exponential
D.	linear
Answer» C. exponential

Discussion

33.	Hard magnetic materials are used for manufacturing ___________.
A.	temporary magnets
B.	permanent magnets
C.	conductors
D.	insulator
Answer» C. conductors

Discussion

34.	A magnetic circuit requires 800 AT to produce a certain quantity of flux in the magnetic circuit. If its excitation coil has 100 turns and 5-ohm resistance, the voltage to be applied in the exciting coil is _____.
A.	60 V
B.	40 V
C.	80 V
D.	8 V
Answer» C. 80 V

Discussion

35.	A conductor is rotated in a magnetic field. The direction of the induced emf can be found by application of
A.	Farraday Law
B.	Lenz's Law
C.	Fleming's right hand rule
D.	Fleming's left hand rule
Answer» D. Fleming's left hand rule

Discussion

36.	A solenoid having N turns and I amperes will have an inductance of ________ henry.
A.	\(\frac{{{\rm{N}}\phi }}{{\rm{I}}}\)
B.	N/I
C.	I/N
D.	\(\frac{{{\rm{I}}\phi }}{{\rm{N}}}\)
Answer» B. N/I

Discussion

37.	In magnetic circuits, due to fringing effect, the following is true if Bc represents core flux density and Bg represents average air gap flux density.
A.	Bc = Bg
B.	Bc > Bg
C.	Bc < Bg
D.	Bg remains unaffected due to fringing
Answer» C. Bc < Bg

Discussion

38.	A 600-turn coil has a resistance of 7 Ohms and an inductance of 0.8 H. If one-fifth of the turns are removed, then determine the new inductance (in H)
A.	0.512
B.	1.25
C.	2
D.	2.5
Answer» B. 1.25

Discussion

39.	A magnetic ring has a mean circumference of 20 cm and a cross-section of 20 cm2 and has 800 numbers of turns of wire. When the exciting current is 5 A, the flux is 2 mWb. The relative permeability of iron is nearly
A.	3.98
B.	398
C.	0.398
D.	39.8
Answer» E.

Discussion

40.	Consider a circular conductor and a bar magnet as shown below and state which of the following statements is/are true?I) The induced current in the conductor when the north pole of bar magnet is pushed towards the conductor is in an anticlockwise direction.II) The induced current in the conductor when the south pole of bar magnet is pushed away from the conductor is in a clockwise direction.III) The induced current in the conductor when the south pole of bar magnet is pushed away from the conductor is in an anticlockwise direction.IV) The induced current in the conductor when the north pole of bar magnet is pushed away from the conductor is in an anticlockwise direction.
A.	I and III only
B.	I and II only
C.	III and IV only
D.	II and IV only
Answer» B. I and II only

Discussion

41.	An electric charge moves with a constant velocity(v) parallel to the lines of force of a uniform magnetic field B. The force experienced by the charge is _________.
A.	eVB
B.	e/BV
C.	eV/B
D.	0
Answer» E.

Discussion

42.	A wire of length 50 cm moves at right angles to its length at 50 m/s in a uniform magnetic field of density 1T. Find the EMF induced in the conductor when the direction of motion is inclined at 30° to the direction of the field.
A.	25 V
B.	6.75 V
C.	12.5 V
D.	50 V
Answer» D. 50 V

Discussion

43.	A conductor of length 0.5 m moves in a uniform magnetic field of density 1.1 T at certain velocity. Find the velocity if the induced voltage in the conductor is 16.5 V and the direction of motion is perpendicular to the field.
A.	30 m/s
B.	60 m/s
C.	40 m/s
D.	50 m/s
Answer» B. 60 m/s

Discussion

44.	If NΦ = linkage flux, then the linkage flux per unit current is defined as:
A.	inductive reactance
B.	magneto motive force
C.	leakage coefficient
D.	inductance
Answer» E.

Discussion

45.	Compute the work done to move a conductor of length 0.10 m carrying a current of 45 A in âz (positive z direction). Consider the magnetic field density \(\left( {\vec{B}} \right)\) as 2.50 × 10-3 âr in cylindrical co-ordinate system and the conductor is placed at radial length r = 0.03 m along the z axis.
A.	4.26 × 10-3 J
B.	-4.26 × 10-3J
C.	2.13 × 10-3 J
D.	-2.13 × 10-3 J
Answer» E.

Discussion

46.	A coil is said to have a self-inductance of 1 henry if an EMF of 1 volt is induced in it when the current flowing through it changes at the rate of ___________.
A.	1 A / second
B.	1 mA / second
C.	1 mA / min
D.	1 A / min
Answer» B. 1 mA / second

Discussion

47.	A coil of 1000 turns is wound on a core. A current of 1 A flowing through the coil creates a core flux of 1 mWb. What is the energy stored in the magnetic field?
A.	\(\frac{1}{4}J\)
B.	\(\frac{1}{2}J\)
C.	1J
D.	2J
Answer» C. 1J

Discussion

48.	A conductor of length 0.6 m is situated at the right angle to a uniform magnetic field of flux density 4 Wb/sq. m. The conductor is moving with a velocity of 50 m/s. Calculate the emf induced (in V) n the conductor.
A.	100
B.	115
C.	118
D.	120
Answer» E.

Discussion

49.	AT/m is the unit of
A.	m.m.f.
B.	reluctance
C.	magnetizing force
D.	magnetic flux density
Answer» D. magnetic flux density

Discussion

50.	Magnetostriction is the effect produced when change of magnetization in magnetic material results in
A.	change of permeability
B.	change in dimensions
C.	change of temperature
D.	change of magnetic field strength
Answer» C. change of temperature

Discussion

Explore topic-wise MCQs in Electromagnetic Theory.

A coil of 500 turns wound on a core of non-magnetic material has an inductance of 20 mH. The average value of the EMF induced when a current of 2 A is reversed in 5 ms is:

Hysteresis loss in a transformer is proportional to which of the following quantity?

Magnetic field intensity has the dimension

A long straight wire carries a current I = 10 A. At what distance is the magnetic field H = 1 A/m?

Magnetic field intensity (H) of a long conductor carrying current ‘I’ at a distance ‘r’ is _________

"In all cases electromagnetic induction, an induced voltage will cause a current to flow in a closed circuit in such a direction that the magnetic field which is caused by that current will oppose the change that produces the current", is the original statement of _____.

A conductor of length 100 cm moves at right angle to a uniform field flux density of 1.5 Wb/m2 with a velocity of 50 m/s. The e.m.f. induced in the conductor will be

A 25 μC point charge is located at origin. Calculate electric flux passing through the portion of sphere defined by r = 20 cm, bounded by θ = 0 and π rad, ϕ = 0 and π/2 rad.

A solenoid has 4000 turns over it with inductance of 0.126 H. The energy stored in the magnetic field, when a current of 2 A flows in the solenoid will be

A magnetic circuit of reluctance 3000 A-turns/Wb is wounded by a wire of 400 turns. Determine the average emf induced (in V) in the coil, if a current of 2 A is flowing in the coil is reversed in 15 s.

In a magnetic tape blanks are provided at the _____.

If a circular conductor carries a current of ‘I’ ampere having radius ‘r’ meter, then the magnetizing force at the center of the coil is given by ;

Magnetic field intensity (H), within a magnetic material where, M = 150 A/m, μ = 1.5 × 10-5 H/m, μr = 30;

A long solenoid of radius R, having N turns per unit length carries a time depend current I(t) = I0 sin (ωt). The magnitude of induced electric field at a distance R/2 radially from the axis of the solenoid is

Determine the magnetic field strength (in A/m) of a material when the intensity of magnetization of the material is 0.084 Amp/m and the magnetic susceptibility of the material is 0.0012.

A coil wound over an iron carries a certain current and establishes flux in the ring. If the area of a cross-section of the ring is doubled, the flux in the core _____.

Permanent Magnets are made of

A conductor of length 1 m moves at right angles to a uniform magnetic field of flux density 2 Wb/m2 with a velocity of 50 m/s. What is the value of the induced e.m.f., when the conductor moves at an angle of 30° to the direction of the field?

Magnetic flux density is quantified in terms of ______.

A current flows in a conductor from east to west. The direction of magnetic fields at a point above the conductor is

Calculate the value of flux leakage coefficient, if ϕg is the air gap flux and ϕa is the flux in iron core.

For magnetic circuits, the relationship which is similar to application of Ohm’s Law is, (where ϕ is flux, S is reluctance)

If l is the length of a conductor lying within the magnetic field and I is the ampere current carried by it, then magnitude of the force experienced by it is:

Consider the following statements regarding an ideal core material:1. It has very high permeability.2. It loses all its magnetism when there is no current flow.3. It does not saturate easily.Which of the above statements are correct?

Permeance is inversely related to

Determine the magnetic susceptibility of a material, if the field strength of the material is 0.8 × 105 A – m-1 and the magnitude of magnetization is 0.97 × 105 A – m-1

In ferroelectric materials, the hysteresis loop is the __________ function of the applied electric field.

Hard magnetic materials are used for manufacturing ___________.

A magnetic circuit requires 800 AT to produce a certain quantity of flux in the magnetic circuit. If its excitation coil has 100 turns and 5-ohm resistance, the voltage to be applied in the exciting coil is _____.

A conductor is rotated in a magnetic field. The direction of the induced emf can be found by application of

A solenoid having N turns and I amperes will have an inductance of ________ henry.

In magnetic circuits, due to fringing effect, the following is true if Bc represents core flux density and Bg represents average air gap flux density.

A 600-turn coil has a resistance of 7 Ohms and an inductance of 0.8 H. If one-fifth of the turns are removed, then determine the new inductance (in H)

A magnetic ring has a mean circumference of 20 cm and a cross-section of 20 cm2 and has 800 numbers of turns of wire. When the exciting current is 5 A, the flux is 2 mWb. The relative permeability of iron is nearly

An electric charge moves with a constant velocity(v) parallel to the lines of force of a uniform magnetic field B. The force experienced by the charge is _________.

A wire of length 50 cm moves at right angles to its length at 50 m/s in a uniform magnetic field of density 1T. Find the EMF induced in the conductor when the direction of motion is inclined at 30° to the direction of the field.

A conductor of length 0.5 m moves in a uniform magnetic field of density 1.1 T at certain velocity. Find the velocity if the induced voltage in the conductor is 16.5 V and the direction of motion is perpendicular to the field.

If NΦ = linkage flux, then the linkage flux per unit current is defined as:

A coil is said to have a self-inductance of 1 henry if an EMF of 1 volt is induced in it when the current flowing through it changes at the rate of ___________.

A coil of 1000 turns is wound on a core. A current of 1 A flowing through the coil creates a core flux of 1 mWb. What is the energy stored in the magnetic field?

A conductor of length 0.6 m is situated at the right angle to a uniform magnetic field of flux density 4 Wb/sq. m. The conductor is moving with a velocity of 50 m/s. Calculate the emf induced (in V) n the conductor.

AT/m is the unit of

Magnetostriction is the effect produced when change of magnetization in magnetic material results in