# Electronics and Communication Engineering - Electromagnetic Field Theory

6.
∇ . = 0 is frequently known as
Laplace equation
Poisson's equation
none of the above
Explanation:

Equation of continuity

∇ x J = 0.

7.
A rhombic antenna is a
resonant antenna
non-resonant antenna
coupled antenna
none of the above
Explanation:
No answer description is available. Let's discuss.

8.
Which of the following relations is valid?
∇ x ∇ x = ∇(∇ . ) - ∇2 A
∇ x ∇ x = ∇(∇ x ) - ∇2 A
∇ x ∇ x = ∇2 A - (∇)
none of the above
Explanation:
No answer description is available. Let's discuss.

9.
Diffraction of electromagnetic waves
may occur around the edge of a sharp obstacle
is caused by reflections from the ground
arises only with the spherical wave fronts
will occur when the waves pass through a large slot
Explanation:
No answer description is available. Let's discuss.

10.
The magnetic field intensity vector of a plane wave is given by (x, y, z, t) = 10 sin (5000t + 0.004x + 30 ), where denotes unit vector in y direction the wave is propagating with a phase velocity.
5 x 104 m/sec
-3 x 108 m/sec
-1.25 x 107 m/sec
3 x 108 m/sec