Micro Wave Engineering 4

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Electronic Engineering MCQ Question Papers: ENTC, IT Interview Placement

Subject: Micro Wave Engineering 4

Part 4: List for questions and answers of Micro Wave Engineering

 

Q1. A cavity resonator is

a) A hollow metallic enclosure

b) A hollow enclosure having magnetic material as its walls

c) A hollow enclosure having dielectric material as its walls

d) Either (b) or (c)

 

Q2. If antenna diameter is increased four times, the maximum range is increased by a factor of

a) Squre root of 2

b) 2

c) 4

d) 0.2

 

Q3. Assertion (a): gunn diode is a transferred electron device Reason (r): a gunn oscillator uses the phenomenon of 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

 

Q4. Atomic and molecular resonance is observed in many substances

a) At microwave frequencies

b) At low frequencies

c) At frequencies used in am broadcast

d) At both (b) and (c)

 

Q5. The semiconductor diode which can be used in switching circuit in microwave range is

a) Pin diode

b) Varactor diode

c) Tunnel diode

d) Gunn diode

 

Q6. A line has an attenuation of 0.054 np/m. The attenuation in decibels is

a) 4.7 db/m

b) 0.47 db/m

c) 0.54 db/m

d) 5.4 db/m 

 

Q7. A reflex klystron oscillator uses

a) One cavity resonator

b) Two cavity resonators

c) Three cavity resonators

d) None of the above

 

Q8. A coaxial rf cable has a characteristic impedance of 50 ohm and c equal to 40 pf/m. The inductance is

a) 1  µ h/m

b) 10  µ h/m

c) 0.1  µh/m

d)  µ h/m

 

Q9. To couple a coaxial line to a parallel wire line it is best to use

a) Slotted line

b) Balun

c) Directional coupler

d) ?/4 transformer

 

Q10. If vswr is infinite, the transmission line is terminated in

a) Short circuit

b) Complex impedance

c) Open circuit

d) Either (a) or (c)

 

Q11. The number of tv channels which can be accommodated in a spectrum of 300 mhz is about

a) 5

b) 10

c) 50

d) 200

 

Q12. Roughly the time required for microwave cooking as compared to conventional cooking is

a) About twice

b) About half

c) About 10 times

d) About one-tenth 

 

Q13. If the minimum range of a radar is to be doubled, the peak power has to be increased by a factor of

a) 2

b) 4

c) 8

d) 16

 

Q14. Which mode has the lowest cut off frequency in circular wave guides?

a) Te01

b) Te11

c) Te20

d) Te21

 

Q15. Assertion (a): klystron amplifiers use one or more intermediate cavities in addition to buncher and catcher cavity

Reason (r): when one or more intermediate cavities are used the bandwidth can be increased

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. A reflex klystron oscillator is a

a) Low power device

b) High power device

c) High efficiency device

d) Both (a) and (b)

 

Q17. Impedance inversion may be obtained with

a) A short circuited stub

b) A quarter wave line

c) An open circuited stub

d) A half wave line

 

Q18. Power gain of a multicavity klystron amplifier is

a) More than 30 db

b) Causes retardation of all electrons

c) Causes acceleration of some electrons and retardation of others

d) None of the above 

 

Q19. Assertion (a): for high frequency lines inductive reactance is very high as compared to ac resistance Reason (r): due to skin effect ac resistance of line is higher than dc 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

 

Q20. Which one of the following is not a negative resistance device?

a) Gunn diode

b) Tunnel diode

c) Impatt diode

d) Varactor diode 

 

Part 4: List for questions and answers of Micro Wave Engineering

 

Q1. Answer: a

 

Q2. Answer: c

 

Q3. Answer: b

 

Q4. Answer: a

 

Q5. Answer: a

 

Q6. Answer: b

 

Q7. Answer: a

 

Q8. Answer: c

 

Q9. Answer: b

 

Q10. Answer: d

 

Q11. Answer: c

 

Q12. Answer: d

 

Q13. Answer: d

 

Q14. Answer: b

 

Q15. Answer: a

 

Q16. Answer: a

 

Q17. Answer: b

 

Q18. Answer: a

 

Q19. Answer: b

 

Q20. Answer: d