Electromagnetics Field (3140912) MCQs

MCQs of Steady Magnetic Fields

Showing 21 to 30 out of 43 Questions
21.
Magnetic flux density of the material when, E = 3Sinyāx+4Coszāy+exāz is
(a) ∫(4Sinzāx−exāy−3Cos yāz)dt
(b) −∫(4Sinzāx−exāy−3Cos yāz)dt
(c) ∫(4Sinzāx−exāy+3Cos yāz)dt
(d) −∫(4Sinzāx+exāy+3Cos yāz)dt
Answer:

Option (b)

22.
Magnetic vector potential is
(a) Scalar quantity
(b) Vector quantity
(c) Varying with time
(d) Always zero
Answer:

Option (b)

23.
Magnetic vector potential for a line current will be inversely proportional to
(a) Current
(b) Current density
(c) Distance
(d) Field intensity
Answer:

Option (c)

24.
Stokes' theorem connects
(a) Line integral and surface integral
(b) Surface integral and volume integral
(c) Line integral and volume integral
(d) Gradient of function its surface integral
Answer:

Option (a)

25.
A solid iron cylinder is placed in a region containing a uniform magnetic field such that the cylinder axis is parallel to the magnetic field direction. The magnetic field lines inside the cylinder will
(a) Bend closer to cylinder axis
(b) Bend far away from the cylinder axis
(c) Remains uniform as before
(d) Ceases to exist inside the cylinder
Answer:

Option (a)

26.
The flux density at a point in space is given by B = 4xāx+2kyāy+8āz Wb/m2. The value of constant k must be equal to
(a) 2
(b) 0.5
(c) −2
(d) −0.5
Answer:

Option (c)

27.
Which of the following statements holds for the divergence of electric and magnetic flux densities?
(a) Both are zero
(b) Zero for static density but non-zero for time varying density
(c) Zero for electric flux density
(d) Zero for magnetic flux density
Answer:

Option (d)

28.
The line integral of the vector potential A around the boundary of a surface S represents
(a) Flux through surface S
(b) Flux density in surface S
(c) Filed intensity
(d) Current density
Answer:

Option (a)

29.
If flux density is 10 Wb/m2 and the area of the coil is 2 m2, then the flux is
(a) 10 Wb
(b) 20 Wb
(c) 5 Wb
(d) 40 Wb
Answer:

Option (b)

30.
What will be the flux density in free space for magnetic field,H= 4āx A/m?
(a) 1.6πāx μWb/m2
(b) 16πāx μWb/m2
(c) 0.16πāx μWb/m2
(d) 160πāx μWb/m2
Answer:

Option (a)

Showing 21 to 30 out of 43 Questions