**Anna University Department of Electronics Communication Engineering**

Department : B.E ECE

Semester : V

Year : 3rd yr

Regulation : 2008

Subject Code : EC2305

Subject Name : Transmission Lines and Wave guides

Content : EC2305 Transmission Lines and Wave guides– Important Questions – 1st Edition of 2012.

UNIT I - TRANSMISSION LINE THEORY

1. Obtain the general solution of Transmission line?

2. Explain about waveform distortion and distortion less line condition?

3. Explain about reflection loss?

4. Discuss in details about inductance loading of telephone cables and derive the attenuation constant and phase constant and velocity of signal transmission for the uniformly loaded cable?

5. Derive the equation of attenuation constant and phase constant of TL in terms of R,L, C, G?

6. Explain in details about the reflection on a line not terminated in its characteristic impedance (Z0)?

7. Explain in following terms

(i) Reflection factor (ii) Reflection loss

(iii) Return loss

8. Explain about physical significance of TL?

9. Derive the equation for transfer impedance?

10. Derive the expression for input impedance of lossless line?

11. Explain about telephone cable?

12. Explain about different type of TL?

**UNIT II**

**THE LINE AT RADIO FREQUENCIES**

1. Explain about half wave transformer? (8)

2. Application of smith chart? (8)

3. Explain about voltage and current waveform of dissipation less line?

4. Derive the expression for the input impedance of the dissipation less line and the expression for the input impedance of a quarter wave line. Also discuss the application of quarter wave line?

5. Explain single stub matching on a transmission line and derive the expression and the length of the stub used for matching on a line?

6. Design a single stub match for a load of 150+j225 ohms for a 75 ohms line at 500 MHz using smith chart?

7. A 30 m long lossless transmission line with characteristic impedance (Zo) of 50 ohm is terminated by a load impedance (ZL) = 60 + j40 ohm. The operating wavelength is 90 m. find the input impedance and SWR using smith chart?

8. Explain double stub matching on a transmission line and derive the expression and the length of the stub used for matching on a line?

9. Explain about λ / 8 wave transformer?

10. Explain about properties of smith chart?

** **

**UNIT III**

**GUIDED WAVES **

1. Discuss the characteristics of TE and TM waves and also derive the cut off frequency and phase velocity from the propagation constant?

2. Derive the expression for the field strength for TE waves between parallel plates propagating in Z direction?

3. Derive the expression for attenuation of TM waves in between parallel plates?

4. Derive the expression for attenuation of TE waves in between parallel Plates?

5. Derive the expression for the field strength for TM waves between Parallel plates propagating in Z direction?

6. Obtain the expression for the field components of an electromagnetic wave propagating between a pair of perfectly conducting planes?

7. Derive the expression for wave impedance of TE, TM and TEM wave

between a pair of perfectly conducting planes?

8. Explain about transverse electromagnetic waves between a pair of perfectly conducting planes?

9. Prove that the velocity of propagation?

** **

**UNIT IV - RECTANGULAR WAVEGUIDES**

1. Derive the field configuration, cut off frequency and velocity of propagation for TM waves in rectangular wave – guides?

2. Determine the solution of electric and magnetic fields of TE waves guided along rectangular wave – guides?

3. Explain the wave impedance of a rectangular wave – guide and derive the expression for the wave impedance of TE,TM, and TEM mode?

4. Discuss the characteristics of TE and TM waves and also derive the cut off frequency and phase velocity from the propagation constant?

5. Derive the expression for attenuation of TE10 waves in rectangular wave guide?

6. Derive the expression for attenuation of TM 11 waves in rectangular wave guide?

7. Explain about excitation modes in rectangular wave guide?

8. Explain about dominant mode in rectangular wave guide?

9. Determine the solution of electric and magnetic fields of TM waves guided along rectangular wave – guides?

10. Explain about characteristic impedance in rectangular wave guide?

11. Explain about degenerate mode in rectangular wave guide?

**UNIT V**

**CIRCULAR WAVE GUIDES AND RESONATORS**

1. Derive the Q-factor of a rectangular cavity resonator?

2. Derive the TM wave components in circular wave guides using Bessel functions?

3. What is meant by cavity resonator? Derive the expression for the resonant frequency of the rectangular cavity resonator?

4. Derive the expression for cut off frequency, phase constant and phase

velocity of wave in a circular wave guide?

5. Derive the expression for the resonant frequency of the circular cavity resonator?

6. Derive the expression for the resonant frequency of the semi circular cavity resonator?

7. Derive the TE wave components in circular wave guides using Bessel functions?

8. Derive the expression for the wave impedance in circular wave guide?

9. Derive the field strength or equation in cylindrical co – ordinates systems?