# Micro Wave Engineering 2

Electronic Engineering MCQ Question Papers: ENTC, IT Interview Placement

Subject: Micro Wave Engineering 2

Part 2: List for questions and answers of Micro Wave Engineering

Q1. A quarter wave line open circuited at far end behaves as

a) Inductance

b) L and c in parallel

c) Capacitance

d) L and c in series

Q2. The diagram to show distance time history of electrons in klystron amplifier is called

a) Apple gate diagram

b) Asynchronous diagram

c) Bunching diagram

d) Velocity modulation diagram

Q3. The frequency of oscillation in a backward wave oscillator can be changed by

a) Varying the voltage which controls beam velocity

b) Varying the beam current

c) Both by varying the beam current and by light varying the voltage which controls beam velocity

d) Changing the rate of thermionic emission

Q4. A line has a phase constant of 29.8 rad/m. At 1000 mhz the wavelength is

a) 29.8 m

b) 2.98 m

c) 2.1 m

d) 0.21 m

Q5. For a 50 ? resistor for 3 ghz application, the stray capacitance should be less than

a) 1 µf

b) 1 nf

c) 1 pf

d) 0.1 pf

Q6. The fabrication of microstrip line is done by

a) Photo etching

b) Printed circuit technique

c) Oxidation

Q7. The action of backward wave oscillator is similar to that of

a) Klystron amplifier

b) Reflex klystron oscillator

c) Twt

d) Magnetron

Q8. A line is excited by a 100 v dc source. If reflection coefficients at both ends are 1 each then

a) There will be no oscillations on line

b) There will be only 1 or 2 oscillations on line

c) There will be a finite number of oscillations on line

d) The oscillations will continue indefinitely

Q9. A 10 km long line has a characteristic impedance of 400 ohms. If line length is 100 km, the characteristic impedance is

a) 4000 ohm

b) 400 ohm

c) 40 ohm

d) 4 ohm

Q10. Which tm mode in rectangular waveguide has lowest cutoff frequency?

a) Tm11

b) Tm01

c) Tm10

d) Tm21

Q11. A resistive microwave load with zl = 150 ohm is connected to 50 ohm coaxial line. Swr is

a) More than 3

b) Less than 3

c) Equal to 3

d) Either (a) or (c)

Q12. Which of the following devices uses a slow wave structure?

a) Klystron two cavity amplifier

b) Klystron multicavity amplifier

c) Reflex klystron oscillator

d) Twt

Q13. In a turnstile antenna two-half wave resonant wire radiators are placed at 90° to each other in the same plane and are excited

a) In phase

b) In phase opposition

c) 90° out of phase with each other

d) 45° out of phase with each other

Q14. A waveguide section in a microwave circuit acts as

a) Lp filter

b) Bandpass filter

c) Hp filter

d) Band stop filter

Q15. The cut off wavelength in circular waveguide

a) Guide diameter

b) Square of guide diameter

c) Cube of guide diameter

d) Square root of guide diameter

Q16. The directive gain of a transmitting antenna is proportional to

a) Its cross-sectional area

b) Square of cross-sectional area

c) Square root of cross-sectional area

d) Cube root of cross-sectional area

Q17. If a line having z0 = 300   0 w is open circuited at far end, vswr is

a) 0

b) 1

c) 8

d) 2

Q18. If f is the frequency of electromagnetic wave, fc is cutoff frequency, then in a rectangular waveguide

a) Attenuation is low when f and fc

b) Attenuation is low when f and fc

c) Attenuation is high when f and fc

d) Either (b) or (c)

Q19. In a loss line rl greater then z0, then

a) Reflection coefficient is zero

b) Reflection coefficient is 8

c) Reflection coefficient is negative

d) Reflection coefficient is positive

Q20. The correct sequence of parts in klystron amplifier are

a) Anode, catcher cavity, cathode, buncher cavity

b) Cathode, buncher cavity, catcher cavity, cavity

c) Anode, buncher cavity, catcher cavity, cathode

d) Cathode, catcher cavity, anode, buncher cavity

Part 2: List for questions and answers of Micro Wave Engineering