### Electromagnetics Objectives Part 01

01 . Mark the correct relation = j.j = k. k = 1

02 . Which of the following relation is valid?i x j = k

03 . Which of the following relation is valid?A x (B x C) = (A.C) B – (A.B) C 4. Which of the following relation is valid? ∇ x ∇ x A = ∇ (∇. A)- ∇2 A

04 . The magnitude of the vector 3ax+4ay-5az is 7.07.

05 . Which of the following represents the Maxwell’s divergence equation for static electric field? ∇ . B = 0

.

06 . Which of the following represents the Maxwell’s curl equation for static magnetic field? ∇x B= μ0 J.

07 . Which of the following represents the Maxwell’s curl equation for static magnetic field? ∇x B= μ0 J.

08 . Conductivity is measured in terms of mhos/metre.

09. The magnitude of the vector cosαax + 2 sinα ay = 7 azwill be 7.21.

10 . Which of the following relation is valid? D=εE.

11 . The component form of the unit vector which is directed along a line from the origin to (-2,1,2).− 𝟐𝟑𝒂𝒙 + 𝟐𝟑 𝒂𝒚+ 𝟐𝟑 𝒂𝒛.

12 . The do product of the vectors A and B when A= 3ay -2ax and B= 2 A will be0.

13 . A medium behaves like dielectric when the displacement current is much greater than the conduction current.

14 . If the magnetic field vector H has only Z component given by H= 3x cosβ + 6y sinγ and if the field is invariant with time, the expression for current density J will be J=-6 k sin γ.

15 . Which of the following field satisfies Maxwell’s equation?
B=8X104 Y2 + 4 X 109t2
E= 9x1010yt ax

16 . The relative dielectric constant of a non-magnetic material through which a uniform plane wave is propagating and intrinsic impedance is 180 Ω will be 2.25.

17 . What is the relative dielectric constant of a non-magnetic material through which a uniform plane wave is propagating if the wave-length at 10Hz is 2 cm? 3.65.

18 . The wavelength in a material for which εR = 4, μR=1, f=3×108 Hz and the loss tangent is 0.01, will be 3.455m.

19 . The percentage of the incident power that is reflected when uniform plane wave travelling in region 1 normally incident on region 2 if region 1 and 2 are respectivelypolysterene and air.

20 . In case of semi-conductors the ratio of conduction current to displacement current is less than 100 but greater than 𝟏𝟏𝟎𝟎.