Electromagnetics Field (3140912) MCQs

MCQs of Steady Magnetic Fields

Showing 31 to 40 out of 43 Questions
31.
If the curl of the magnetic field is 2āx A/m2, the current density is
(a) x A/m2
(b) 0.2āx A/m2
(c) x A/m2
(d) 0.1āx A/m2
Answer:

Option (a)

32.
∫(∇×H)•dS is
(a) Zero
(b) Ienc
(c) J
(d) ∫H•dS
Answer:

Option (a)

33.
The unit of scalar magnetic potential is
(a) Ampere
(b) Volt
(c) Ampere/m
(d) Volt/m
Answer:

Option (a)

34.
∇×∇Vm is
(a) Zero
(b) 2Vm
(c) J
(d) ∇•∇Vm
Answer:

Option (a)

35.
∇×A is
(a) H
(b) B
(c) J
(d) Zero
Answer:

Option (b)

36.
If the magnetic flux density in a medium is given by B = (CosΦ/ρ)āρ, then flux crossing the surface −π/4<Φ<π/4 and 0≤z≤2 is
(a) 2.83 Wb
(b) 2.83 mWb
(c) 2.83 μwb
(d) 2.83 nWb
Answer:

Option (a)

37.
What is the magnetic flux density in free space for magnetic field, H = 3āx+2āy A/m?
(a) 3.7āx−2.5āy μWb/m2
(b) −3.7āx−2.5āy μWb/m2
(c) 3.7āx+2.5āy μWb/m2
(d) −3.7āx+2.5āy μWb/m2
Answer:

Option (c)

38.
What is the magnetic flux density for a medium with μr=3 and H = rSinΦār+2.5rSinΘCosΦāΦ A/m?
(a) 3.14rSinΦār+7.85rSinΘCosΦāΦ μWb/m2
(b) 3.14rSinΦār+7.85rSinΘCosΦāΦ μWb/m2
(c) −3.14rSinΦār+7.85rSinΘCosΦāΦ μWb/m2
(d) −3.14rSinΦār−7.85rSinΘCosΦāΦ μWb/m2
Answer:

Option (a)

39.
For a given magnetic flux density, B = ρāΦ Wb/m2, total flux crossing the surface, Φ = π/2, 1≤ρ≤2 m, 0≤z≤5 m is
(a) 75 Wb
(b) 0.75 Wb
(c) 750 Wb
(d) 7.5 Wb
Answer:

Option (d)

40.
What will be the magnetic flux between the conductors of a coaxial cable of length 10 m?
The radius of the inner conductor is 1 cm and that of the outer conductor is 2 cm. The current enclosed is 2A.
(a) 277 μWb
(b) 0.277 μWb
(c) 27.7 μWb
(d) 2.77 μWb
Answer:

Option (a)

Showing 31 to 40 out of 43 Questions