Micro Wave Engineering 6

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Electronic Engineering MCQ Question Papers: ENTC, IT Interview Placement

Subject: Micro Wave Engineering 6

Part 6: List for questions and answers of Micro Wave Engineering

 

Q1. The radiation resistance of a circular loop of one turn is 0.01 ohm. For 5 turn loop the radiation resistance is

a) 0.002 ohm

b) 0.01 ohm

c) 0.05 ohm

d) 0.25 ohm

 

Q2. As wavelength decrease the size of high directivity antenna

a) Decreases

b) Increases

c) Is not affected

d) Either (b) or (c)

 

Q3. Which of the following modes of transmission will not be supported by a rectangular waveguide?

a) Te15

b) Te12

c) Tm11

d) Tm10

 

Q4. In a circular waveguide with radius r, the dominant mode is

a) Tm01

b) Te01

c) Tm11

d) Te11

 

Q5. A parametric amplifier uses

a) Non linear resistance

b) Non linear reactance

c) Either (a) or (b)

d) Neither (a) nor (b)

 

Q6. Assertion (a): impatt diode can be used in both amplifiers and oscillators Reason (r): impatt diode has a low resistance

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 

 

Q7. Which one of the following can be used for amplification of microwave energy?

a) Twt

b) Magnetron

c) Reflex klystron

d) Gunn diode

 

Q8. At frequencies of 10 mhz and higher the impedance represented by ground is primarity

a) Resistive

b) Inductive

c) Capacitive

d) Partly resistive and partly capacitive

 

Q9. A disadvantage of microstrip line as the connections of compared to strip line is that former

a) Do not lend themselves to printed circuit

b) Are more likely to radiate

c) Are bulky

d) Are more expensive and complex

 

Q10. As frequency increases, the transmission efficiency

a) Decreases

b) Increases

c) Is not affected

d) Either (a) or (c)

 

Q11. If d is diameter of circular waveguide the cutoff wave-length for te11 mode is equal to

a) 1.706 d

b) 2.11 d

c) 0.82 d

d) 0.41 d

 

Q12. The external magnetic field in a magnetron is such that lines are

a) Parallel to the axis of cathode

b) Perpendicular to the axis of cathode

c) Inclined to the axis of cathode

d) Either (b) or (c) 

 

Q13. Varactor diodes use

a) Silicon

b) Gaas

c) Either (a) or (b)

d) Neither (a) nor (b)

 

Q14. Assertion (a): impatt diode is an avalanche diode Reason (r): avalanche breakdown phenomenon occurs when a p-n junction is reverse biased

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

 

Q15. A radar has a maximum range of 120 km. The maximum allowable pulse repetition frequency for unambiguous reception is

a) 1250

b) 330

c) 2500

d) 8330

 

Q16. In a line with finite attenuation

a) Power transmission is least efficient when there are no standing waves on the line

b) Power transmission is most efficient when there are no standing waves on line

c) Load power depends on phase constant

d) Standing waves will always exist on the line

 

Q17. The electric field in a twt due to applied signal

a) Is directed along the helix axis

b) Is directed radially from helix axis

c) Is inclined to the helix axis by about 60â°

d) Is inclined to the helix axis by about 45â°

 

Q18. Satellite communication systems use the frequency band

a) 10 to 20 mhz

b) 50 to 70 mhz

c) 3 to 6 ghz

d) 100 to 120 ghz 

 

Q19. The characteristic impedance of a cable is about

a) 300 ohm

b) 50 ohm

c) 5 ohm

d) 2 ohm

 

Q20. A tr (transmitter receiver) tube has

a) Low loss for low power signals and high

b) High loss for low power signals and low loss for high level signal

c) Low loss for both low level and high level signals

d) High loss for both low level and high level signals 

 

Part 6: List for questions and answers of Micro Wave Engineering

 

Q1. Answer: d

 

Q2. Answer: a

 

Q3. Answer: d

 

Q4. Answer: b

 

Q5. Answer: b

 

Q6. Answer: b

 

Q7. Answer: a

 

Q8. Answer: c

 

Q9. Answer: b

 

Q10. Answer: b

 

Q11. Answer: a

 

Q12. Answer: a

 

Q13. Answer: c

 

Q14. Answer: b

 

Q15. Answer: a

 

Q16. Answer: b

 

Q17. Answer: a

 

Q18. Answer: c

 

Q19. Answer: b

 

Q20. Answer: a