JNTU B.Tech III ELECTROMAGNETIC THEORY AND TRANSMISSION LINES Previous Question Paper (July/August - 2023 - R16)

Calculate the capacitance of the Earth assuming it is a conducting sphere of radius R₀ = 6,400 km.

Can there also be combinations of charge distributions? Give examples.

What is the difference between emf and voltage?

Why is Faraday's law important? What does it add to what we already know from magnetostatics and electrostatics?

Define polarization.

Write the difference between Reflection and Refleciton and Refraction of Plane Waves.

How do you define a finite transmission line?

Plot the voltage, current, line impedance, and reflection coefficient for a line with characteristic impedance Ro, load impedance 2Ro, and VL = Vo.

Write the application areas of Smith chart.

Illustrate Single Matching.

State Coulomb's law. Compare this law with the gravitational law.

The electric flux density outside a conductor is equal to the surface charge density on the conductor's surface. Expound why this must be so.

Derive Poisson's and Laplace's equations in cylindrical coordinates directly, using the expressions for the gradient of a scalar function.

Explain why capacitance is independent of the total charge and potential.

Induced emf can be either dc or ac depending on the arrangement Transformer. Explain.

Describe why the magnetic vector potential is convenient to use in conjunction with the magnetic field.

A conductor of length 2L carries current I and is bent as in Figure. Calculate the magnetic flux density at point P.

Derive the Boundary conditions of the tangential and normal components of Magneto static fields at the boundary between two perfect dielectrics.

Derive the wave equation in E and H for free space conditions.

What is Poynting vector? How is it useful in estimating power flow?

Discuss about the plane wave reflection at oblige incidence on a perfect dielectrics.

Write short notes on (i) Brewster angle (ii) Total Internal Reflection

Derive the expression or attenuation constant and phase constant in a lossy Dielectric medium.

Expound the Distortionless Transmission Line.

Explain why the line parameters calculated per unit length lead to valid line equations even when the wavelength is much shorter than 1 m.

A transmission line has the following parameters: R= 2 ohm/m, G= 0.5 mmho/m, L= 8 nH/m, C= 0.23 pF. If the operating frequency is 1 GHz find the characteristic impedance of the line, propagation constant, attenuation and phase constant.

Describe the voltage reflection coefficient as well as the standing wave ratio. Determine their relationship.

A long power transmission line supplies 1500 MW at 750 kV to a matched load (that is, the load impedance equals the line impedance). (i) Suppose the load is disconnected. What is the reflection coefficient at the load? (ii) Because of a fault on the line, the load changes from the matched condition to ZL = 200 + j100 ohms. What is the reflection coefficient at the load now?

Define Reflection Co-efficient and VSWR of a transmission line loaded with an impedance of zl and obtain an expression for the same in terms of z0 and zl.

A transmission line has propagation constant γ = 0.01 + j0.05, characteristic impedance Zo = 50Ω and a load ZL = 50 + j50 Ω is connected at one end. Calculate: i) The impedance on the line at the load. ii) The impedance at a distance of 10 m from the load. iii) Plot the line impedance as a function of distance from load.