Micro Wave Engineering 1

Electronic Engineering MCQ Question Papers: ENTC, IT Interview Placement

Subject: Micro Wave Engineering 1

Part 1: List for questions and answers of Micro Wave Engineering

Q1. The velocity factor of a transmission line depends on

a) Temperature

b) Skin effect

c) Relative permittivity of dielectric

d) None of the above

Q2. A loss less line of characteristic impedance z0 is terminated in pure reactance of -jz0 value. Vswr is

a) 10

b) 2

c) 1

d) Infinity

Q3. In a klystron amplifier the input cavity is called

a) Buncher

b) Catcher

c) Pierce gun

d) Collector

Q4. In a circular waveguide the dominant mode is

a) Te01

b) Te11

c) Te20

d) Te21

Q5. The reflection coefficient on a line is 0.2  45°. The swr is

a) 0.8

b) 1.1

c) 1.2

d) 1.5

Q6. Microwave resonators are used in

a) Microwave oscillators

b) Microwave narrow band amplifier

c) Microwave frequency metres

d) All of the above

Q7. Assertion (a): twt uses a focussing mechanism to prevent the electron beam from spreading Reason (r): in a twt the electron beam has to travel a much longer distance than in klystron

a) Both a and r are correct and r is correct explanation of a

b) Both a and r are correct but r is not correct explanation of a

c) A is correct but r is wrong

d) A is wrong but r is correct

Q8. In a twt the amplitude of resultant wave travelling down the helix

a) Increases exponentially

b) Increases linearly

c) Decreases exponentially

d) Is almost constant

Q9. Which of the following is not a travelling wave?

a) E = em sin (ßx – ω t)

b) E = em cos (ßx – ω t)

c) E = em sin (ω t – ßx)

d) E = em sin (ßx)

Q10. In a directional coupler

a) Isolation (db) equals coupling plus directivity

b) Coupling (db) equals isolation plus directivity

c) Directivity (db) equals isolation plus coupling

d) Isolation (db) equals (coupling) (directivity)

Q11. As the frequency is increased, the charging mvar in a cable

a) Decreases

b) Increases

c) Remain the same

d) Decreases or remains the scheme

Q12. Loss angle of a good quality cable is about

a) 1°

b) 30°

c) 70°

d) 90°

Q13. In a three cavity klystron amplifier, the oscillations are excited in

a) Input cavity

b) Output cavity

c) Intermediate cavity

d) Both (a) and (b)

Q14. Which of the following lines is non-radiating?

a) Open two wire

b) Coaxial

c) Both

d) None of the above

Q15. Assertion (a): the impedance of a matched load is equal to characteristic impedance of line Reason (r): a matched termination absorbs all the power incident on it

a) Both a and r are correct and r is correct explanation of a

b) Both a and r are correct but r is not correct explanation of a

c) A is correct but r is wrong

d) A is wrong but r is correct

Q16. Skin effect is more pronounced at high frequencies

a) True

b) False

c) Cant defined

d) None of these

Q17. Assertion (a): the phenomenon of differential mobility is called transferred electron effect Reason (r): gaas exhibits transferred electron effect

a) Both a and r are correct and r is correct explanation of a

b) Both a and r are correct but r is not correct explanation of a

c) A is correct but r is wrong

d) A is wrong but r is correct

Q18. Which of the following devices uses a helix?

a) Klystron amplifier

b) Klystron oscillator

c) Twt

d) Both (a) and (b)

Q19. Which of the following parameters is negligible in transmission lines?

a) R

b) L

c) C

d) G

Q20. The width of a radio beam from a 1 m diameter parabolic antenna at 10 ghz is about

a) 100°

b) 50°

c) 5°

d) 1°

Part 1: List for questions and answers of Micro Wave Engineering