0
1.6kviews
Engineering Electromagnetic Question Paper - Jun 19 - Electronics Engineering (Semester 5) - Mumbai University (MU)
1 Answer
0
103views

Engineering Electromagnetic - Jun 19

Electronics Engineering (Semester 5)

Total marks: 80
Total time: 3 Hours
INSTRUCTIONS
(1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Draw neat diagrams wherever necessary.

Attempt any four

1.a. Three equal point charges of $2\small \mu C$ are located at (0,0,0)m , (2,0,0)m and (0,2,0)m respectively in free space. Find out net force on Q4 = $5\small \mu C$ at (2,2,0)m.
(5 marks) 00

1.b. Derive the wave equation for time varying Harmonic fields in free space.
(5 marks) 00

1.c. Compare MOM, FDM, and FEM.
(5 marks) 00

1.d. Explain Beam width of an antenna. An antenna has a field pattern given by $E(\small \theta) = cos^{2} \small\theta $ for $0^{o}\leq90^{o}$ .Find its Half power width.
(5 marks) 00

1.e. Define Critical Frequency and MUF. Calculate the critical frequency where the maximum value of n is 0.9 with a MUF of 10 MHz.
(5 marks) 00

2.a. Given V = 2 $x^{2}y-5xz$ find : v, E, D and $\small \rho V$ at P(-4, 3, 6)m.
(10 marks) 00

2.b. GIven $\overrightarrow{E} = 1.5cos (10^{8}t-\small \beta z)$ $\overrightarrow{a_{x}}$ V/m , Obtain B,H, and D. Assume $\small \epsilon_{r}$ = 1 and $\small \mu_{r = 1}$, and $\small \sigma = 0$
(10 marks) 00

3.a. Derive the boundary conditions for Electric and Magnetic fields at the boundary of two dielectric media.
(10 marks) 00

3.b. In free space, a plane wave with $\overrightarrow{H_{l}} = 10cos (10^{8}t-\small\beta z) \overrightarrow{a_{x}}$ mA/m is incident normally on a lossless medium with $\small \epsilon = \small \epsilon_{0}$ , $\small \mu = \small \mu_{0}$ in region $z \geq 0$ . Determine $H_{r}, E_{r} $for the reflected wave and $H_{t}, E_{t}$ for the transmitted wave.
(10 marks) 00

4.a. Use the Iterative finite difference method and band matrix method to calculate potential at nodes 1 and 2 in the figure shown below:

enter image description here

(10 marks) 00

4.b. State Poynting Theorem and derive an expression for the Poynting vector. Explain the power terms mentioned in the derivation.
(10 marks) 00

5.a. An electric field strength of $10 \small\mu$ V/m is to be measured at an observation point $\small \Theta = \small \pi/2$ , 500 km from a half wave dipole antenna operating in air 50 Mhz. What is the length of the dipole? If the transmission line with $Z_{o} = 75 \Omega$ is connected to the antenna, determine $\small \Gamma$ and standing wave ratio using smith Chart.
(10 marks) 00

5.b. A distortion less line $Z_{o} = 50 \Omega, \small \alpha = 50 Np/m, V = 0.6c$ where c is the speed in light in vacuum . Determine R, L, G C and $\small \lambda$ at 100 MHz.
(10 marks) 00

6.a. Explain the factors affecting the field strength of space wave signal.
(5 marks) 00

6.b. Explain the concept of retarded potential.
(5 marks) 00

6.c. Derive the relationship between effective area and Directivity.
(5 marks) 00

6.d. Write the generalised Maxwell's Equations in point form and integral form.
(5 marks) 00

Please log in to add an answer.