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All questions of Magnetostatics for Electrical Engineering (EE) Exam
Find the current density of a material with resistivity 20 units and electric field intensity 2000 units.- a)400
- b)300
- c)200
- d)100
Correct answer is option 'D'. Can you explain this answer?
Find the current density of a material with resistivity 20 units and electric field intensity 2000 units.
a)
400
b)
300
c)
200
d)
100
|
Lavanya Menon answered |
Answer: d
Explanation: The current density is given by J = σ E, where σ is the conductivity. Thus resistivity ρ = 1/σ. J = E/ρ = 2000/20 = 100 units.
Explanation: The current density is given by J = σ E, where σ is the conductivity. Thus resistivity ρ = 1/σ. J = E/ρ = 2000/20 = 100 units.
Find the magnetic flux density of the material with magnetic vector potential A = y i + z j + x k.- a)i + j + k
- b)–i – j – k
- c)–i-j
- d)–i-k
Correct answer is option 'B'. Can you explain this answer?
Find the magnetic flux density of the material with magnetic vector potential A = y i + z j + x k.
a)
i + j + k
b)
–i – j – k
c)
–i-j
d)
–i-k
|
Gate Funda answered |
Answer: b
Explanation: The magnetic flux density is the curl of the magnetic vector potential. B = Curl(A). Thus Curl(A) = i(-1) – j(1) + k(-1) = -i – j – k. We get B = -i – j – k.
Explanation: The magnetic flux density is the curl of the magnetic vector potential. B = Curl(A). Thus Curl(A) = i(-1) – j(1) + k(-1) = -i – j – k. We get B = -i – j – k.
The induced voltage will oppose the flux producing it. State True/False. - a)True
- b)False
Correct answer is option 'A'. Can you explain this answer?
The induced voltage will oppose the flux producing it. State True/False.
a)
True
b)
False
|
Yash Patel answered |
Answer: a
Explanation: According to Lenz law, the induced voltage acts in such a way that it opposes the flux producing it. This is indicated by a negative sign.
Explanation: According to Lenz law, the induced voltage acts in such a way that it opposes the flux producing it. This is indicated by a negative sign.
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)93.68
Correct answer is option 'A'. Can you explain this answer?
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)
93.68
|
Ravi Singh answered |
Answer: a
Explanation: 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.
Explanation: 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.
Biot Savart law in magnetic field is analogous to which law in electric field?- a)Gauss law
- b)Faraday law
- c)Coulomb’s law
- d)Ampere law
Correct answer is option 'C'. Can you explain this answer?
Biot Savart law in magnetic field is analogous to which law in electric field?
a)
Gauss law
b)
Faraday law
c)
Coulomb’s law
d)
Ampere law
|
Zoya Sharma answered |
Answer: c
Explanation: Biot Savart law states that the magnetic flux density H = I.dl sinθ/4πr2, which is analogous to the electric field F = q1q2/4πεr2, which is the Coulomb’s law.
Explanation: Biot Savart law states that the magnetic flux density H = I.dl sinθ/4πr2, which is analogous to the electric field F = q1q2/4πεr2, which is the Coulomb’s law.
Using Maxwell equation which of the following cannot be calculated directly?- a)B
- b)D
- c)A
- d)H
Correct answer is option 'C'. Can you explain this answer?
Using Maxwell equation which of the following cannot be calculated directly?
a)
B
b)
D
c)
A
d)
H
|
|
Yash Patel answered |
Answer: c
Explanation: The Maxwell equations can be used to compute E,H,D,B and J directly. It is not possible to find the magnetic vector potential A directly.
Explanation: The Maxwell equations can be used to compute E,H,D,B and J directly. It is not possible to find the magnetic vector potential A directly.
The Faraday’s law states about which type of EMF?- a)Transformer EMF
- b)Back EMF
- c)Generator EMF
- d)Secondary EMF
Correct answer is option 'A'. Can you explain this answer?
The Faraday’s law states about which type of EMF?
a)
Transformer EMF
b)
Back EMF
c)
Generator EMF
d)
Secondary EMF
|
Sanya Agarwal answered |
Answer: a
Explanation: The stationary loop in a varying magnetic field results in an induced emf due to the change in the flux linkage of the loop. This emf is called as induced or transformer EMF.
Explanation: The stationary loop in a varying magnetic field results in an induced emf due to the change in the flux linkage of the loop. This emf is called as induced or transformer EMF.
Calculate the emf when the flux is given by 3sin t + 5cos t- a)3cos t – 5sin t
- b)-3cos t + 5sin t
- c)-3sin t – 5cos t
- d)3cos t + 5sin t
Correct answer is option 'B'. Can you explain this answer?
Calculate the emf when the flux is given by 3sin t + 5cos t
a)
3cos t – 5sin t
b)
-3cos t + 5sin t
c)
-3sin t – 5cos t
d)
3cos t + 5sin t
|
Muskaan Nair answered |
Answer: b
Explanation: The electromotive force is given by Vemf = -dλ/dt. Thus Vemf = -dλ/dt = -(3cos t – 5sin t) = -3cos t + 5sin t.
Explanation: The electromotive force is given by Vemf = -dλ/dt. Thus Vemf = -dλ/dt = -(3cos t – 5sin t) = -3cos t + 5sin t.
In an field having a force of 12N and distance 20cm, the torque will be- a)0.24
- b)2.4
- c)24
- d)12/20
Correct answer is option 'B'. Can you explain this answer?
In an field having a force of 12N and distance 20cm, the torque will be
a)
0.24
b)
2.4
c)
24
d)
12/20
|
|
Sanvi Kapoor answered |
Answer: b
Explanation: 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.
Explanation: 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.
Find the force on a conductor of length 12m and magnetic flux density 20 units when a current of 0.5A is flowing through it.- a)60
- b)120
- c)180
- d)200
Correct answer is option 'B'. Can you explain this answer?
Find the force on a conductor of length 12m and magnetic flux density 20 units when a current of 0.5A is flowing through it.
a)
60
b)
120
c)
180
d)
200
|
|
Sanvi Kapoor answered |
Answer: b
Explanation: The force on a conductor is given by F = BIL, where B = 20, I = 0.5 and L = 12. Force F = 20 X 0.5 x 12 = 120 N.
Explanation: The force on a conductor is given by F = BIL, where B = 20, I = 0.5 and L = 12. Force F = 20 X 0.5 x 12 = 120 N.
Find the force that exists in an electromagnetic wave.- a)Electrostatic force
- b)Magnetostatic force
- c)Lorentz force
- d)Electromotive force
Correct answer is option 'C'. Can you explain this answer?
Find the force that exists in an electromagnetic wave.
a)
Electrostatic force
b)
Magnetostatic force
c)
Lorentz force
d)
Electromotive force
|
|
Rhea Reddy answered |
Answer: c
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.
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.
Find the correct relation between current density and magnetization.- a)J = Grad(M)
- b)J = Div(M)
- c)J = Curl(M)
- d)M = Curl(J)
Correct answer is option 'C'. Can you explain this answer?
Find the correct relation between current density and magnetization.
a)
J = Grad(M)
b)
J = Div(M)
c)
J = Curl(M)
d)
M = Curl(J)
|
|
Ravi Singh answered |
Answer: c
Explanation: The curl of the magnetization gives the magnetic field intensity theoretically. From Maxwell equation, we can correlate that with the current density (Ampere law)
Explanation: The curl of the magnetization gives the magnetic field intensity theoretically. From Maxwell equation, we can correlate that with the current density (Ampere law)
Calculate the energy when the magnetic intensity and magnetic flux density are 15 and 65 respectively.- a)755
- b)487.5
- c)922
- d)645
Correct answer is option 'B'. Can you explain this answer?
Calculate the energy when the magnetic intensity and magnetic flux density are 15 and 65 respectively.
a)
755
b)
487.5
c)
922
d)
645
|
Gargi Mishra answered |
Answer: b
Explanation: The magnetic energy can also be written as E = 0.5 μH2 = 0.5 BH, since B = μH. On substituting B = 65 and H = 15 we get E = 0.5 x 65 x 15 = 487.5 units.
Explanation: The magnetic energy can also be written as E = 0.5 μH2 = 0.5 BH, since B = μH. On substituting B = 65 and H = 15 we get E = 0.5 x 65 x 15 = 487.5 units.
If ∫ H.dL = 0, then which statement will be true? - a)E = -Grad(V)
- b)B = -Grad(D)
- c)H = -Grad(Vm)
- d)D = -Grad(A)
Correct answer is option 'C'. Can you explain this answer?
If ∫ H.dL = 0, then which statement will be true?
a)
E = -Grad(V)
b)
B = -Grad(D)
c)
H = -Grad(Vm)
d)
D = -Grad(A)
|
Madhurima Das answered |
Answer: c
Explanation: The given condition shows that the magnetic field intensity will be the negative gradient of the magnetic vector potential.
Explanation: The given condition shows that the magnetic field intensity will be the negative gradient of the magnetic vector potential.
Ampere turn is equivalent to which element?- a)Sφ
- b)S/φ
- c)φ/S
- d)S
Correct answer is option 'A'. Can you explain this answer?
Ampere turn is equivalent to which element?
a)
Sφ
b)
S/φ
c)
φ/S
d)
S
|
Swati Shah answered |
Answer: a
Explanation: Ampere turn refers to the current element, which is the product of the turns and the current. It is given by NI. From the definition of reluctance, S = NI/φ. Thus NI = Sφ is the best equivalent.
Explanation: Ampere turn refers to the current element, which is the product of the turns and the current. It is given by NI. From the definition of reluctance, S = NI/φ. Thus NI = Sφ is the best equivalent.
Which of the following relation will hold good?- a)D = μ H
- b)B = ε E
- c)E = ε D
- d)B = μ H
Correct answer is option 'D'. Can you explain this answer?
Which of the following relation will hold good?
a)
D = μ H
b)
B = ε E
c)
E = ε D
d)
B = μ H
|
|
Mahi Bose answered |
Answer: d
Explanation: The magnetic flux density is the product the permeability and the magnetic field intensity. This statement is always true for any material (permeability).
Explanation: The magnetic flux density is the product the permeability and the magnetic field intensity. This statement is always true for any material (permeability).
Find the flux density B when the potential is given by x i + y j + z k in air. - a)12π x 10-7
- b)-12π x 10-7
- c)6π x 10-7
- d)-6π x 10-7
Correct answer is option 'B'. Can you explain this answer?
Find the flux density B when the potential is given by x i + y j + z k in air.
a)
12π x 10-7
b)
-12π x 10-7
c)
6π x 10-7
d)
-6π x 10-7
|
Arya Mukherjee answered |
Answer: b
Explanation: The field intensity H = -Grad(V). Since the given potential is a position vector, the gradient will be 3 and H = -3. Thus the flux density B = μH = 4π x 10-7 x (-3) = -12π x 10-7 units.
Explanation: The field intensity H = -Grad(V). Since the given potential is a position vector, the gradient will be 3 and H = -3. Thus the flux density B = μH = 4π x 10-7 x (-3) = -12π x 10-7 units.
Find the magnetic field intensity when the current density is 0.5 units for an area up to 20 units.- a)10
- b)5
- c)20
- d)40
Correct answer is option 'A'. Can you explain this answer?
Find the magnetic field intensity when the current density is 0.5 units for an area up to 20 units.
a)
10
b)
5
c)
20
d)
40
|
|
Jatin Mukherjee answered |
Answer: a
Explanation: We know that ∫ H.dl = I. By Stoke’s law, we can write Curl(H) = J. In integral form, H = ∫ J.ds, where J = 0.5 and ds is defined by 20 units. Thus H = 0.5 x 20 = 10 units.
Explanation: We know that ∫ H.dl = I. By Stoke’s law, we can write Curl(H) = J. In integral form, H = ∫ J.ds, where J = 0.5 and ds is defined by 20 units. Thus H = 0.5 x 20 = 10 units.
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)1.8
Correct answer is option 'D'. Can you explain this answer?
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)
1.8
|
Mrinalini Sen answered |
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.
100 maxwells = _______ magnetic line(s).- a)10
- b)100
- c)1000
- d)1
Correct answer is option 'B'. Can you explain this answer?
100 maxwells = _______ magnetic line(s).
a)
10
b)
100
c)
1000
d)
1
|
Manoj Chaudhary answered |
Answer:
In order to understand the answer to this question, it is important to have a basic understanding of magnetic lines of force and the unit of magnetic flux, which is the Maxwell.
Magnetic Lines of Force:
Magnetic lines of force, also known as magnetic field lines, are imaginary lines used to represent the direction and strength of a magnetic field. These lines are used to visualize and describe the magnetic field around a magnet or a current-carrying conductor.
The Maxwell:
The Maxwell is a unit of magnetic flux, which measures the amount of magnetic field passing through a given area. It is equivalent to one magnetic line of force.
Conversion:
Given that 100 Maxwells is the quantity to be converted, we need to determine how many magnetic lines of force are equivalent to 100 Maxwells.
Since 1 Maxwell is equivalent to one magnetic line of force, 100 Maxwells would be equal to 100 magnetic lines of force.
Therefore, the correct answer is option 'B', which states that 100 Maxwells is equal to 100 magnetic lines of force.
In order to understand the answer to this question, it is important to have a basic understanding of magnetic lines of force and the unit of magnetic flux, which is the Maxwell.
Magnetic Lines of Force:
Magnetic lines of force, also known as magnetic field lines, are imaginary lines used to represent the direction and strength of a magnetic field. These lines are used to visualize and describe the magnetic field around a magnet or a current-carrying conductor.
The Maxwell:
The Maxwell is a unit of magnetic flux, which measures the amount of magnetic field passing through a given area. It is equivalent to one magnetic line of force.
Conversion:
Given that 100 Maxwells is the quantity to be converted, we need to determine how many magnetic lines of force are equivalent to 100 Maxwells.
Since 1 Maxwell is equivalent to one magnetic line of force, 100 Maxwells would be equal to 100 magnetic lines of force.
Therefore, the correct answer is option 'B', which states that 100 Maxwells is equal to 100 magnetic lines of force.
Which of the following is true regarding magnetic lines of force?- a)Real
- b)Imaginary
- c)Does not exist
- d)Parallel to field
Correct answer is option 'B'. Can you explain this answer?
Which of the following is true regarding magnetic lines of force?
a)
Real
b)
Imaginary
c)
Does not exist
d)
Parallel to field
|
Suyash Joshi answered |
Answer: b
Explanation: Magnetic Lines of Force is a an imaginary line representing the direction of magnetic field such that the tangent at any point is the direction of the field vector at that point.
Explanation: Magnetic Lines of Force is a an imaginary line representing the direction of magnetic field such that the tangent at any point is the direction of the field vector at that point.
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)24
Correct answer is option 'C'. Can you explain this answer?
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)
24
|
Nikhil Iyer answered |
Answer: c
Explanation: The electric force is given by F = qE, where q = 2C and E = 6 units. Thus we get F = 2 x 6 = 12 units.
Explanation: The electric force is given by F = qE, where q = 2C and E = 6 units. Thus we get F = 2 x 6 = 12 units.
Find the displacement current when the flux density is given by t3 at 2 seconds. - a)3
- b)6
- c)12
- d)27
Correct answer is option 'C'. Can you explain this answer?
Find the displacement current when the flux density is given by t3 at 2 seconds.
a)
3
b)
6
c)
12
d)
27
|
|
Alok Khanna answered |
Answer: c
Explanation: The displacement current is given by Jd = dD/dt. Thus Jd = 3t2. At time t = 2, we get Jd = 3(2)2= 12A.
Explanation: The displacement current is given by Jd = dD/dt. Thus Jd = 3t2. At time t = 2, we get Jd = 3(2)2= 12A.
Find the magnetic field of a finite current element with 2A current and height 1/2π is- a)1
- b)2
- c)1/2
- d)1/4
Correct answer is option 'A'. Can you explain this answer?
Find the magnetic field of a finite current element with 2A current and height 1/2π is
a)
1
b)
2
c)
1/2
d)
1/4
|
|
Divya Singh answered |
Answer: a
Explanation: The magnetic field due to a finite current element is given by H = I/2πh. Put I = 2 and h = 1/2π, we get H = 1 unit.
Explanation: The magnetic field due to a finite current element is given by H = I/2πh. Put I = 2 and h = 1/2π, we get H = 1 unit.
The value of ∫ H.dL will be- a)J
- b)I
- c)B
- d)H
Correct answer is option 'B'. Can you explain this answer?
The value of ∫ H.dL will be
a)
J
b)
I
c)
B
d)
H
|
Bhavana Reddy answered |
Answer: b
Explanation: By Stoke’s theorem, ∫ H.dL = ∫ Curl(H).dS and from Ampere’s law, Curl(H) = J. Thus ∫ H.dL = ∫ J.dS which is nothing but current I.
Explanation: By Stoke’s theorem, ∫ H.dL = ∫ Curl(H).dS and from Ampere’s law, Curl(H) = J. Thus ∫ H.dL = ∫ J.dS which is nothing but current I.
Calculate the magnetic field at a point on the centre of the circular conductor of radius 2m with current 8A.- a)1
- b)2
- c)3
- d)4
Correct answer is option 'B'. Can you explain this answer?
Calculate the magnetic field at a point on the centre of the circular conductor of radius 2m with current 8A.
a)
1
b)
2
c)
3
d)
4
|
|
Niharika Basu answered |
Answer: b
Explanation: The magnetic field due to a point in the centre of the circular conductor is given by H = I/2a. Put I = 8A and a = 2m, we get H = 8/4 = 2 units.
Explanation: The magnetic field due to a point in the centre of the circular conductor is given by H = I/2a. Put I = 8A and a = 2m, we get H = 8/4 = 2 units.
The line integral of the magnetic field intensity is given by- a)Turns
- b)Flux density
- c)MMF
- d)Current element
Correct answer is option 'D'. Can you explain this answer?
The line integral of the magnetic field intensity is given by
a)
Turns
b)
Flux density
c)
MMF
d)
Current element
|
|
Sakshi Roy answered |
Answer: d
Explanation: The line integral of H is given by ∫H. dl. From Ampere law it can be related to the current density and hence the current element NI for a coil of N turns. Thus, ∫H. dl = NI.
Explanation: The line integral of H is given by ∫H. dl. From Ampere law it can be related to the current density and hence the current element NI for a coil of N turns. Thus, ∫H. dl = NI.
The magnetostatics highly relies on which property?- a)Resistance
- b)Capacitance
- c)Inductance
- d)Moment
Correct answer is option 'C'. Can you explain this answer?
The magnetostatics highly relies on which property?
a)
Resistance
b)
Capacitance
c)
Inductance
d)
Moment
|
|
Sahana Sarkar answered |
Answer: c
Explanation: The magnetostatics highly relies on the inductance of the magnetic materials, which decides its behavior in the influence of magnetic field.
Explanation: The magnetostatics highly relies on the inductance of the magnetic materials, which decides its behavior in the influence of magnetic field.
Which of the following relations is correct?- a)NI = Sφ
- b)NS = Iφ
- c)Nφ = SI
- d)NI = S/φ
Correct answer is option 'A'. Can you explain this answer?
Which of the following relations is correct?
a)
NI = Sφ
b)
NS = Iφ
c)
Nφ = SI
d)
NI = S/φ
|
|
Muskaan Nair answered |
Answer: a
Explanation: The reluctance is also defined by the ratio of the current element to the flux. In other words, mmf = NI. Thus S = NI/φ. We get the relation NI = Sφ.
Explanation: The reluctance is also defined by the ratio of the current element to the flux. In other words, mmf = NI. Thus S = NI/φ. We get the relation NI = Sφ.
Choose the best relation. - a)A = -Div(V)
- b)V = Curl(A)
- c)H = -Grad(V)
- d)V = Div(E)
Correct answer is option 'C'. Can you explain this answer?
Choose the best relation.
a)
A = -Div(V)
b)
V = Curl(A)
c)
H = -Grad(V)
d)
V = Div(E)
|
|
Athul Banerjee answered |
Answer: c
Explanation: For any magnetic field, the magnetic field intensity will be the negative gradient of the potential of the field. This is given by H = -Grad(V).
Explanation: For any magnetic field, the magnetic field intensity will be the negative gradient of the potential of the field. This is given by H = -Grad(V).
Find the force due to a current element of length 2cm and flux density of 12 tesla. The current through the element will be 5A.- a)1 N
- b)1.2 N
- c)1.4 N
- d)1.6 N
Correct answer is option 'B'. Can you explain this answer?
Find the force due to a current element of length 2cm and flux density of 12 tesla. The current through the element will be 5A.
a)
1 N
b)
1.2 N
c)
1.4 N
d)
1.6 N
|
|
Manoj Mehra answered |
The force due to a current element is given by F = BI x L. Thus F = 12 x 5 x 0.02 = 1.2 units.
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)65.235
Correct answer is option 'A'. Can you explain this answer?
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)
65.235
|
Jaya Datta answered |
Answer: a
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.
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.
Find the magnetic field when a circular conductor of very high radius is subjected to a current of 12A and the point P is at the centre of the conductor.- a)1
- b)∞
- c)0
- d)-∞
Correct answer is option 'C'. Can you explain this answer?
Find the magnetic field when a circular conductor of very high radius is subjected to a current of 12A and the point P is at the centre of the conductor.
a)
1
b)
∞
c)
0
d)
-∞
|
|
Srishti Choudhary answered |
Answer: c
Explanation: The magnetic field of a circular conductor with point on the centre is given by I/2a. If the radius is assumed to be infinite, then H = 12/2(∞) = 0.
Explanation: The magnetic field of a circular conductor with point on the centre is given by I/2a. If the radius is assumed to be infinite, then H = 12/2(∞) = 0.
Calculate the magnetic energy when the magnetic intensity in air is given as 14.2 units(in 10-4 order)- a)1.26
- b)2.61
- c)6.12
- d)1.62
Correct answer is option 'A'. Can you explain this answer?
Calculate the magnetic energy when the magnetic intensity in air is given as 14.2 units(in 10-4 order)
a)
1.26
b)
2.61
c)
6.12
d)
1.62
|
|
Parth Ghoshal answered |
Answer: a
Explanation: The magnetic energy is given by E = 0.5 μ H2. Put H = 14.2 and in air μ = 4π x 10-7, we get E = 0.5 x 4π x 10-7 x 14.22 = 1.26 x 10-4 units.
Explanation: The magnetic energy is given by E = 0.5 μ H2. Put H = 14.2 and in air μ = 4π x 10-7, we get E = 0.5 x 4π x 10-7 x 14.22 = 1.26 x 10-4 units.
Find the internal field when the applied field is 12 units, molecular field constant is 0.1 units and the magnetization is 74 units.- a)86
- b)62
- c)752
- d)19.4
Correct answer is option 'D'. Can you explain this answer?
Find the internal field when the applied field is 12 units, molecular field constant is 0.1 units and the magnetization is 74 units.
a)
86
b)
62
c)
752
d)
19.4
|
|
Samridhi Bose answered |
Answer: d
Explanation: From Curie law, the internal field of a magnetic material is given by H = Ho + χ M, where χ is the molecular field constant. Put χ = 0.1, M = 74 and Ho = 12, we get H = 12 + (0.1)74 = 19.4 units.
Explanation: From Curie law, the internal field of a magnetic material is given by H = Ho + χ M, where χ is the molecular field constant. Put χ = 0.1, M = 74 and Ho = 12, we get H = 12 + (0.1)74 = 19.4 units.
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)50
Correct answer is option 'A'. Can you explain this answer?
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)
50
|
|
Krish Saini answered |
Answer: a
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.
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.
Find the energy of a coil of inductance 18mH and current passing through it 1.25A.(in 10-3order) - a)14.06
- b)61
- c)46.1
- d)28.12
Correct answer is option 'A'. Can you explain this answer?
Find the energy of a coil of inductance 18mH and current passing through it 1.25A.(in 10-3order)
a)
14.06
b)
61
c)
46.1
d)
28.12
|
|
Divya Nair answered |
Answer: a
Explanation: The magnetic energy possessed by a coil is given by E = 0.5 x LI2. Put L = 18 x 10-3 and I = 1.25, thus we get E = 0.5 x 18 x 10-3 x 1.252 = 14.06 x 10-3 units.
Explanation: The magnetic energy possessed by a coil is given by E = 0.5 x LI2. Put L = 18 x 10-3 and I = 1.25, thus we get E = 0.5 x 18 x 10-3 x 1.252 = 14.06 x 10-3 units.
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)91.2
Correct answer is option 'A'. Can you explain this answer?
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)
91.2
|
Aman Datta answered |
Answer: a
Explanation: 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.
Explanation: 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.
The resistance in a magnetic material is called as- a)Capacitance
- b)Inductance
- c)Reluctance
- d)Magnetic resistance
Correct answer is option 'C'. Can you explain this answer?
The resistance in a magnetic material is called as
a)
Capacitance
b)
Inductance
c)
Reluctance
d)
Magnetic resistance
|
|
Sakshi Tiwari answered |
The reluctance of a magnetic material is the ability of the material to oppose the magnetic flux. It is the ratio of the magnetic motive force mmf to the flux.
Find the Maxwell law derived from Ampere law.- a)Div(I) = H
- b)Div(H) = J
- c)Curl(H) = J
- d)Curl(B) = D
Correct answer is option 'C'. Can you explain this answer?
Find the Maxwell law derived from Ampere law.
a)
Div(I) = H
b)
Div(H) = J
c)
Curl(H) = J
d)
Curl(B) = D
|
|
Mahesh Datta answered |
Maxwell's law is an important law in electromagnetism that relates the magnetic field and its sources. It is derived from Ampere's law, which describes the magnetic field generated by a current-carrying wire. Maxwell's law is given by:
Curl(H) = J
Explanation:
Curl(H) is the curl of the magnetic field H. It describes how the magnetic field changes in space. J is the current density, which describes the amount of current flowing through a given area. The equation states that the curl of the magnetic field is equal to the current density, which means that the magnetic field is generated by the current flowing through a wire.
Maxwell's law is important because it relates the magnetic field and its sources. It is one of the four Maxwell's equations that describe the behavior of electric and magnetic fields. The other three equations are Gauss's law, Gauss's law for magnetism, and Faraday's law of induction. Together, these four equations form the foundation of electromagnetism and are used to describe a wide range of phenomena, from the behavior of electric motors to the propagation of electromagnetic waves.
Conclusion:
In conclusion, Maxwell's law is derived from Ampere's law and relates the magnetic field and its sources. It is one of the four Maxwell's equations that describe the behavior of electric and magnetic fields. The equation states that the curl of the magnetic field is equal to the current density, which means that the magnetic field is generated by the current flowing through a wire.
Curl(H) = J
Explanation:
Curl(H) is the curl of the magnetic field H. It describes how the magnetic field changes in space. J is the current density, which describes the amount of current flowing through a given area. The equation states that the curl of the magnetic field is equal to the current density, which means that the magnetic field is generated by the current flowing through a wire.
Maxwell's law is important because it relates the magnetic field and its sources. It is one of the four Maxwell's equations that describe the behavior of electric and magnetic fields. The other three equations are Gauss's law, Gauss's law for magnetism, and Faraday's law of induction. Together, these four equations form the foundation of electromagnetism and are used to describe a wide range of phenomena, from the behavior of electric motors to the propagation of electromagnetic waves.
Conclusion:
In conclusion, Maxwell's law is derived from Ampere's law and relates the magnetic field and its sources. It is one of the four Maxwell's equations that describe the behavior of electric and magnetic fields. The equation states that the curl of the magnetic field is equal to the current density, which means that the magnetic field is generated by the current flowing through a wire.
The H quantity is analogous to which component in the following?- a)B
- b)D
- c)E
- d)V
Correct answer is option 'C'. Can you explain this answer?
The H quantity is analogous to which component in the following?
a)
B
b)
D
c)
E
d)
V
|
|
Harshad Singh answered |
Answer: c
Explanation: The H quantity refers to magnetic field intensity in the magnetic field. This is analogous to the electric field intensity E in the electric field.
Explanation: The H quantity refers to magnetic field intensity in the magnetic field. This is analogous to the electric field intensity E in the electric field.
Two coupled coils with L1 = 0.5 H and L2 = 4.0 H have a co-efficient of coupling 0.8. Find maximum value of the inductance EMF in the coil 2 if a current of i1 = 20 sin 314t A is passed in coil 1.- a)22.6 V
- b)444 V
- c)7.1 kV
- d)355 V
Correct answer is option 'C'. Can you explain this answer?
Two coupled coils with L1 = 0.5 H and L2 = 4.0 H have a co-efficient of coupling 0.8. Find maximum value of the inductance EMF in the coil 2 if a current of i1 = 20 sin 314t A is passed in coil 1.
a)
22.6 V
b)
444 V
c)
7.1 kV
d)
355 V
|
|
Sahil Datta answered |
Given data:
L1 = 0.5 H (inductance of coil 1)
L2 = 4.0 H (inductance of coil 2)
k = 0.8 (coefficient of coupling)
i1 = 20 sin 314t A (current through coil 1)
To find:
Maximum value of the induced EMF in coil 2.
Formula:
The mutual inductance (M) between two coils is given by:
M = k * sqrt(L1 * L2)
The induced EMF in the second coil is given by:
e2 = -M * di1/dt
where di1/dt is the rate of change of current through coil 1.
Calculation:
Using the formula for mutual inductance, we can calculate the value of M as follows:
M = k * sqrt(L1 * L2)
= 0.8 * sqrt(0.5 * 4.0)
= 0.8 * sqrt(2.0)
≈ 0.8 * 1.414
≈ 1.131 H
Since the current through coil 1 is given by i1 = 20 sin 314t A, we can calculate the rate of change of current as follows:
di1/dt = d/dt (20 sin 314t)
= 20 * d/dt (sin 314t)
= 20 * 314 * cos 314t A/s
The maximum value of cos 314t is 1, so we can substitute this value to calculate the maximum rate of change of current:
di1/dt = 20 * 314 * 1
= 6280 A/s
Finally, we can calculate the maximum value of the induced EMF in coil 2 using the formula:
e2 = -M * di1/dt
= -1.131 * 6280 V
≈ -7091.48 V
The negative sign indicates that the induced EMF in coil 2 is in the opposite direction to the change in current in coil 1.
Since the maximum value of the induced EMF is given as a positive value, we take the absolute value:
|e2| ≈ 7091.48 V
Therefore, the maximum value of the induced EMF in coil 2 is approximately 7.1 kV (kilovolts). Hence, the correct answer is option C.
L1 = 0.5 H (inductance of coil 1)
L2 = 4.0 H (inductance of coil 2)
k = 0.8 (coefficient of coupling)
i1 = 20 sin 314t A (current through coil 1)
To find:
Maximum value of the induced EMF in coil 2.
Formula:
The mutual inductance (M) between two coils is given by:
M = k * sqrt(L1 * L2)
The induced EMF in the second coil is given by:
e2 = -M * di1/dt
where di1/dt is the rate of change of current through coil 1.
Calculation:
Using the formula for mutual inductance, we can calculate the value of M as follows:
M = k * sqrt(L1 * L2)
= 0.8 * sqrt(0.5 * 4.0)
= 0.8 * sqrt(2.0)
≈ 0.8 * 1.414
≈ 1.131 H
Since the current through coil 1 is given by i1 = 20 sin 314t A, we can calculate the rate of change of current as follows:
di1/dt = d/dt (20 sin 314t)
= 20 * d/dt (sin 314t)
= 20 * 314 * cos 314t A/s
The maximum value of cos 314t is 1, so we can substitute this value to calculate the maximum rate of change of current:
di1/dt = 20 * 314 * 1
= 6280 A/s
Finally, we can calculate the maximum value of the induced EMF in coil 2 using the formula:
e2 = -M * di1/dt
= -1.131 * 6280 V
≈ -7091.48 V
The negative sign indicates that the induced EMF in coil 2 is in the opposite direction to the change in current in coil 1.
Since the maximum value of the induced EMF is given as a positive value, we take the absolute value:
|e2| ≈ 7091.48 V
Therefore, the maximum value of the induced EMF in coil 2 is approximately 7.1 kV (kilovolts). Hence, the correct answer is option C.
Find the magnetic moment of a material with magnetization 5 units in a volume of 35 units.- a)7
- b)1/7
- c)15
- d)175
Correct answer is option 'D'. Can you explain this answer?
Find the magnetic moment of a material with magnetization 5 units in a volume of 35 units.
a)
7
b)
1/7
c)
15
d)
175
|
|
Mahi Bose answered |
Answer: d
Explanation: The magnetization is the ratio of the magnetic moment and the volume. To get moment, put M = 5 and V = 35, thus moment will be 5 x 35 = 175 units.
Explanation: The magnetization is the ratio of the magnetic moment and the volume. To get moment, put M = 5 and V = 35, thus moment will be 5 x 35 = 175 units.
Compute the power consumed by a material with current density 15 units in an area of 100 units. The potential measured across the material is 20V.- a)100kJ
- b)250kJ
- c)30kJ
- d)15kJ
Correct answer is option 'C'. Can you explain this answer?
Compute the power consumed by a material with current density 15 units in an area of 100 units. The potential measured across the material is 20V.
a)
100kJ
b)
250kJ
c)
30kJ
d)
15kJ
|
|
Shivam Ghosh answered |
Answer: c
Explanation: Power is given by, P= V X I, where I = J X A is the current.
Thus power P = V X J X A = 20 X 15 X 100 = 30,000 joule = 30kJ.
Explanation: Power is given by, P= V X I, where I = J X A is the current.
Thus power P = V X J X A = 20 X 15 X 100 = 30,000 joule = 30kJ.
The flux lines of two energised coils overlapping on each other will give- a)Series aiding
- b)Shunt aiding
- c)Series opposing
- d)Shunt opposing
Correct answer is option 'A'. Can you explain this answer?
The flux lines of two energised coils overlapping on each other will give
a)
Series aiding
b)
Shunt aiding
c)
Series opposing
d)
Shunt opposing
|
|
Sanskriti Kaur answered |
Answer: a
Explanation: Flux lines are the magnetic lines of force of a magnetic material. Since the flux is overlapping, the total flux of the two coils together will be high. Thus it is an aiding flux. Also this type of overlapping is possible only when the two coils are back to back or in series connection.
Explanation: Flux lines are the magnetic lines of force of a magnetic material. Since the flux is overlapping, the total flux of the two coils together will be high. Thus it is an aiding flux. Also this type of overlapping is possible only when the two coils are back to back or in series connection.
Electric field will be maximum outside the conductor and magnetic field will be maximum inside the conductor. State True/False. - a)True
- b)False
Correct answer is option 'A'. Can you explain this answer?
Electric field will be maximum outside the conductor and magnetic field will be maximum inside the conductor. State True/False.
a)
True
b)
False
|
|
Madhurima Das answered |
Explanation:
Electric field and magnetic field are two fundamental concepts in electromagnetism. In the case of a conductor, the distribution of electric and magnetic fields is unique.
Electric Field:
- The electric field is maximum outside the conductor. This is because the charges on the surface of the conductor redistribute themselves in such a way that the electric field inside the conductor is zero.
- This phenomenon is known as electrostatic shielding, where the charges rearrange themselves to cancel out the external electric field inside the conductor.
Magnetic Field:
- In contrast to the electric field, the magnetic field is maximum inside the conductor. When a current flows through a conductor, a magnetic field is generated around it according to Ampere's law.
- Inside the conductor, the magnetic field lines are concentrated due to the flow of current. This results in a higher magnetic field strength inside the conductor compared to outside.
Conclusion:
- Therefore, it is true that the electric field is maximum outside the conductor, while the magnetic field is maximum inside the conductor. This distinction is essential in understanding the behavior of electromagnetic fields around conductors.
In air, the tangential component of flux density is continuous at the boundary. State True/False.- a)True
- b)False
Correct answer is option 'A'. Can you explain this answer?
In air, the tangential component of flux density is continuous at the boundary. State True/False.
a)
True
b)
False
|
|
Mayank Sengupta answered |
Answer: a
Explanation: Since the tangential component of the magnetic field intensity will be continuous and B = μH, in air, the tangential component of the flux density will also be continuous.
Explanation: Since the tangential component of the magnetic field intensity will be continuous and B = μH, in air, the tangential component of the flux density will also be continuous.
In electric fields, D= ε E. The correct expression which is analogous in magnetic fields will be- a)H = μ B
- b)B = μ H
- c)A = μ B
- d)H = μ A
Correct answer is option 'B'. Can you explain this answer?
In electric fields, D= ε E. The correct expression which is analogous in magnetic fields will be
a)
H = μ B
b)
B = μ H
c)
A = μ B
d)
H = μ A
|
|
Tanishq Chauhan answered |
Answer: b
Explanation: In electric fields, the flux density is a product of permittivity and field intensity. Similarly, for magnetic fields, the magnetic flux density is the product of permeability and magnetic field intensity, given by B= μ H.
Explanation: In electric fields, the flux density is a product of permittivity and field intensity. Similarly, for magnetic fields, the magnetic flux density is the product of permeability and magnetic field intensity, given by B= μ H.
Calculate the power of a material with electric field 100 units at a distance of 10cm with a current of 2A flowing through it.- a)10
- b)20
- c)40
- d)80
Correct answer is option 'B'. Can you explain this answer?
Calculate the power of a material with electric field 100 units at a distance of 10cm with a current of 2A flowing through it.
a)
10
b)
20
c)
40
d)
80
|
|
Dipanjan Nambiar answered |
Answer: b
Explanation: Power is defined as the product of voltage and current.
P = V X I, where V = E X d. Thus P = E X d X I = 100 X 0.1 X 2 = 20 units.
Explanation: Power is defined as the product of voltage and current.
P = V X I, where V = E X d. Thus P = E X d X I = 100 X 0.1 X 2 = 20 units.
The inductance is the measure of- a)Electric charges stored by the material
- b)Emf generated by energising the coil
- c)Magnetic field stored by the material
- d)Magnetization of dipoles
Correct answer is option 'B'. Can you explain this answer?
The inductance is the measure of
a)
Electric charges stored by the material
b)
Emf generated by energising the coil
c)
Magnetic field stored by the material
d)
Magnetization of dipoles
|
|
Partho Saha answered |
Answer: b
Explanation: The inductance is a property of an electric conductor/coil which measures the amount of emf generated by passing current through the coil.
Explanation: The inductance is a property of an electric conductor/coil which measures the amount of emf generated by passing current through the coil.
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Electromagnetic Fields Theory (EMFT)
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