JNTUK/JNTUGV Electromagnetic Waves and Transmission Lines - Important Exam Questions
UNIT I:
- Define phase velocity and group velocity. Derive the relation between them.
- What are the conditions for a line to be lossless and distortionless?
- Explain the significance of primary and secondary constants of a transmission line.
- Derive the expression for the propagation constant of a transmission line.
- Draw and explain the T and π equivalent circuits of a transmission line.
UNIT II:
- Explain the concept of VSWR. Derive its relation with reflection coefficient.
- Using the Smith Chart, determine input impedance of a λ/4 line terminated with a load.
- Draw the reflection coefficient curve for an open-circuited and short-circuited line.
- Explain how UHF transmission lines act as circuit elements with practical examples.
- Design a quarter wave transformer for matching a 100 Ω line to a 50 Ω load.
- Explain stub matching and how it is implemented in practical lines.
UNIT III:
- Explain the electric field due to a parallel plate capacitor. Derive capacitance per unit length.
- State and derive Gauss Law. Apply it to calculate field due to a uniformly charged sphere.
- State and derive Coulomb’s Law. How is it related to Gauss Law?
- Define electric potential and derive its relation with electric field.
- Write and explain Poisson’s and Laplace’s equations. Give one application of each.
UNIT IV:s
- State and derive Biot-Savart Law. Use it to find magnetic field at center of circular loop.
- State Amperé’s Circuital Law. Apply it to find magnetic field inside a long solenoid.
- What is magnetic scalar potential? Compare it with vector potential.
- Explain Faraday’s Law of electromagnetic induction with an example.
- Why is Amperé’s Law inconsistent for time-varying fields? Explain displacement current.
UNIT V:
- Derive wave propagation equations for lossy and lossless dielectrics.
- Explain the behavior of uniform plane waves in free space.
- What is the critical angle? Derive the condition for total internal reflection.
- State and explain Poynting Theorem. Define and interpret the Poynting vector.
- What is skin depth? Derive its expression for good conductors.
- Explain the different types of polarization with examples.