QUIZ 1

ECEC6503 TRANSMISSION LINES AND WAVEGUIDES

HAVE A CALCULATOR

1. Which of the following shows the real part of the propagation constant?

(A) Variation of voltage and current on basic unit.

(B) Variation of phase shift/position of voltage.

(C) Reduction in voltage, current values of signal amplitude.

(D) Reduction of only voltage amplitude.

2. What is the purpose of an Attenuator? (A)To increase signal strength. (B) To provide impedance matching. (C) To decrease reflections. (D) To decrease value of signal strength.

3. Which of the following is correct when the transmission line is terminated by a characteristic Impedance?

(A) There is no reflection of the incident wave. (B) The reflection is maximum due to

termination. (C) There are a large number of maximum and

minimum on the line. (D) The incident current is zero for any applied

signal.

4. What type of distortion arises when the waves are not attenuated equally?

(A) Delay distortion (B) Phase distortion (C) Frequency distortion (D) All the above

5. Which of the following factor does not depend on frequency?

(A) Primary constants (B) Velocity (C) Wavelength (D)Secondary constants

6. Which of the following defines the condition for a line becomes distortion less?

(A) It is properly matched (B) It is terminated into Zo (C) LG = CR (D) LR = GC

7. Find the value of reflection co efficient if the line has Zo = 300Ω and ZL = 150Ω?

(A) 1 (B) 0.5 (C) 0.3 (D) ∞

8. What is the status of the characteristic impedance of a distortion less line?

(A) Real (B) Inductive (C) Capacitive (D) Complex

9. How a transmission line works? (A) Attenuator (B) LPF (C) HPF (D) Neither of the above

10. At what frequency attenuation is more in open line transmission systems?

(A) lower frequencies (B) medium frequencies (C) higher frequencies (D) remains constant

11.What is the velocity of propagation in a lossless transmission line?

12. Find which of the given ratio defines voltage reflection coefficient?

A. Incident wave to reflected wave B. Reflected wave to incident wave C. Incident wave to absorbed wave D. Absorbed wave to incident wave

13. Which one of the following conditions will not guarantee a distortion less Transmission Line?

(A) R=0, G=0 (B) LG=RC (C) R >>ωL, G >>ωC (D) R <<ωL, G <<ωC

14. Which of the following statement is correct, when the characteristic impedance of the line is equal to the load impedance?

(A) all the energy will pass to the earth(B) all the energy will be lost in transmission losses(C) the system will resonate badly(D) all the energy sent will be absorbed by the load.

15. Which of the following condition is suitable for a properly terminated line?

(A) ZR=ZO

(B) Z/R > ZO

(C) ZR < ZO

(D) ZR =Z0 = 0.

16. Which of the following factor produces the distortion in transmission line?

(A) Delay distortion (B) Phase distortion (C) Frequency distortion (D) All the above

17. What type of line appear to be of finite length terminated with Z0 to the sending end generator?

A. Infinite line B. Finite line C. Short circuit line D. Open circuit line

18.Which of the following defines the distance wave travels along the line while the phase angle

is changing through 2π radians?A.Velocity B.Wavelength C.Time D.Frequency

19. What is the equation for a characteristic impedance Zo in terms of impedance and admittance?

20. What is the equation for a Propagation constant of a transmission line in terms of impedance and admittance?

21. For which type of wave the voltage or current decreases in amplitude with increasing distance from the load ?

(A)incident wave(B) medium wave(C) reflected wave(D) none of above

22. What is the equation for a characteristic impedance Zo in terms of open & short circuited line?

23. What is the general parameters of a distributed transmission line?

(a) R&L only(b) L&C only(c) C&G only(d) R, L, C&G

24. For which type of wave the voltage or current decreases in amplitude with increasing distance from the source ?

(a) Incident wave(b) medium wave(c) reflected wave(d) none of above

25. Find the characteristic impedance of the line If Zoc = 120Ω and Zsc = 30 Ω?

(A) 30 Ω (B) 60 Ω (C) 120 Ω(D) 150 Ω

26. For a line of characteristic impedance, Z O terminated in a load, ZR such that ZR > ZO , the Voltage Standing Wave Ratio (VSWR) is given by

27. Consider a transmission line of characteristic impedance 50 ohms and the line is terminated at one end by +j50 ohms, the VSWR produced in the transmission line will be

(A) +1 (B) (B) zero (C) infinity (D) -1

28. What is the value of VSWR when the line is in open circuit condition?

A) 0 B) 1C) ∞ D) –1

29. What is the value of the reflection coefficient of a transmission line with a short-circuited load?

(A) 0(B) ∞ (C) 1 <0° (D) 1 <180°

30. What is the value of characteristic impedance when Zoc = 120Ω and

Zsc = 30Ω?(A) 30 Ω (B) 60Ω (C) 120 Ω (D) 150 Ω

31.At what condition the reflection coefficient of a line is equal to −1?

(A)Open circuited (B) Short circuited (C) Terminated in Zo (D) Of infinite length.

32. If a transmission line of length less than λ/4 is short circuited, it behaves as

(A) Pure capacitive reactance.(B) Series resonant circuit.(C) Parallel resonant circuit.(D) Pure inductive reactance.

33.What is the value of the Input impedance of a short-circuited lossless line with length λ/4 ?

(A) Z o (B) zero (C) infinity (D) Z0 2

34. What is the value of the Input impedance of a open-circuited lossless line with length λ /4 ?

(A) Z o(B) zero (C) infinity (D) Z0 2

35. For a transmission line, open circuit and short circuit impedances are 20Ω and 5Ω. The characteristic impedance of the line is

(A) 100 Ω (B) 50 Ω(C) 25 Ω (D) 10 Ω.

36. If K is the reflection coefficient and S is the Voltage standing wave ratio, then

37. What is the value of Voltage standing wave ratio, when Zo = 300<0Ω and ZL = 150<0Ω?

(A) 1 (B) 0.5(C) 2 (D) ∞

38. When the reflection take place in the line?

(A)ZR=0

(B) ZR= ∞

(C) ZR=0 and ZR= ∞

(D) ZR=Zo

39.At what condition the maximum power is absorbed by one network from other, joined to it at two terminals ?(a) impedance of one= complex conjugate of other

(b) impedance of one =square root of other

(c) impedance of one =same as other(d) none of above

40.What is the range of Voltage standing wave ratio ?

(a) 0 to 1(b) 1 to infinity(c) 0 to infinity(d) -1 to +1

41. What is the value of the reflection coefficient when the line is properly terminated with Z0?

(A) 0(B) 1(C) 2 (D) ∞

42.What is called as nodes?a) Point of zero voltage or current b) Point of maximum voltage or

current c) Point of minimum voltage or current

(d) none of above

43.What is called as antinodes?a) Point of zero voltage or current b) Point of maximum voltage or current

c) Point of minimum voltage or current

(d) none of above

44. What is the value of two successive voltage maxima?

a)λ/2b)λ/4c)λ/8d)λ

45. What is the value of two successive voltage minima?

a)λ/2b)λ/4c)λ/8d)λ

46. For a line of characteristic impedance, Z O terminated in a load, ZR such that ZR < ZO , the Voltage Standing Wave Ratio (VSWR) is given by

47. What is the value of VSWR when the line is in short circuit condition?

A) 0 B) 1C) ∞ D) –1

48. What is the value of the reflection coefficient of a transmission line with a open-circuited load?

(A) 0(B) ∞ (C) 1 <0° (D) 0.1 <180°

49.At what condition the reflection coefficient of a line is equal to 1?

(A)Open circuited. (B) Short circuited. (C) Terminated in Zo(D) Of infinite length.

50. What is the range of reflection coefficient ?(a) 0 to 1(b) 1 to infinity(c) 0 to infinity

(d) -1 to +1