Electromagnetic Field Theory MCQ Questions & Answers | ECE

The voltage reflection coefficient at the load end of a transmission line is

In air the lossless transmission line of length 50 cm with L = 10 μH/m, C = 40 pF/m is operated at 25 MHz. Its electrical path length is

For a wave travelling in negative Z direction the value of $$\frac{{{\text{Ey}}}}{{{\text{Hx}}}}$$  is:

A coaxial-cable with an inner diameter of 1 mm and outer diameter of 2.4 mm is filled with a dielectric of relative permittivity 10.89. Given $${\mu _0} = 4\pi \times {10^{ - 7}}{\text{H/m}},\,{\varepsilon _0} = \frac{{{{10}^{ - 9}}}}{{36\pi }}{\text{F/m}}{\text{.}}$$
The characteristic impedance of the cable is

The frequency of a sound wave is 25 Hz and its wavelength is 4 m. What is the distance travelled by the sound wave in 2?

From a solution of wave equation in a conducting medium we can determine various parameters. In the light of this, match List-I with List-II and select the correct answer using the options given below the lists:

List-I (Parameter)	List-II (Expression)
a. Propagation constant	1. $${\left( {\frac{2}{{\omega \mu \sigma }}} \right)^{\frac{1}{2}}}$$
b. Skin depth	2. $${\left( {\frac{{\omega {\mu _0}}}{{2\sigma }}} \right)^{\frac{1}{2}}}$$
c. Sheet resistance	3. $${\left( {j\omega {\mu _0}\sigma } \right)^{\frac{1}{2}}}$$
	4. $${\left( {\frac{{\omega {\mu _0}\sigma }}{2}} \right)^{ - \frac{1}{2}}}$$

The mode used in the laboratory bench is

Consider a rectangular coordinate system (x, y, z) with unit vectors a_x, a_y and a_z. A plane wave travelling in the region z ≥ 0 with electric field vector E = 10cos(2 × 10⁸t + βz)a_y is incident normally on the plane at z = 0, where β is the phase constant. The region z ≥ 0 is in the free space and the region z < 0 is filled with a lossless medium (permittivity ε = ε₀, permeability µ = 4µ₀, where ε₀ = 8.85 × 10¹² F/m and µ₀ = 4π × 10^-7 H/m).
The value of the reflection coefficient is

If a right hand circularly polarised wave is incident on a perfect conductor. The reflected wave is:

The maximum usable frequency of an ionospheric layer at 60° incidence at with 8 MHz critical frequency is