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This set of Radiation and Microwave Techniques Multiple Choice Questions & Answers (MCQs) focuses on Radiation And Microwave Techniques Set 4
Q1 | cm and b = 1.5 cm with μ = 1 and ε = 2.25 is
- 377 ohm
- 327 ohm
- 227 ohm
- 127 ohm
Q2 | 75GHz?
- 9.2 cm
- 3.2 cm
- 0.6 m
- 12 cm
Q3 | 5 cm and 1 cm respectively is
- 4.5 ghz
- 5 ghz
- 5.5 ghz
- 6 ghz
Q4 | 5 GHz is
- 1 cm
- 2 cm
- 3 cm
- 4 cm
Q5 | A major disadvantage of klystron amplifier is
- low power gain
- low bandwidth
- high source power
- design complexity
Q6 | A PIN diode consists of........number of semiconductor layers.
- three
- two
- four
- one
Q7 | The resistance of the PIN diode with positive bias voltage
- increases
- decreases
- remains constant
- insufficient data
Q8 | GaAs is used in the fabrication of GUNN diodes because
- gaas is cost effective
- it less temperature sensitive
- it has low conduction band electrons
- less forbidden energy gap
Q9 | The number of modes of operation for n type GaAs Gunn diode is
- two
- three
- four
- five
Q10 | The number of semiconductor layers in IMPATT diode is:
- two
- three
- four
- none of the mentioned
Q11 | The cavity resonator
- is equivalent to an lc resonant circuit
- in a reflect klystron has its output taken from the reflector plate
- produces a frequency which is independent of the cavity size.
- has a low q factor for narrow operation.
Q12 | A traveling-wave tube (TWT) amplifies by virtue of
- the absorption of energy by the signal from an electron stream
- the effect of an external magnetic field
- the energy contained the cavity resonators
- the energy liberated form the collector
Q13 | Which of the following is used as a high power microwave oscillator?
- thyratron
- magnetron
- klystron
- reflex-klystron
Q14 | The characterstic impedance of a transmission line depends upon
- shape of the conductor
- surface treatment of the conductor
- conductivity of the material
- geometrical configuration of conductors
Q15 | In order to reduce skin effect at ultra high frequencies,
- conductors are painted
- conductors are anodized
- copper rodes with silver plating are used
- copper lubes with silver plating are used
Q16 | Which of the following are constants of transmission lines
- resistance
- inductance
- capacitance
- all of the above
Q17 | Indicate the false statement. The SWR on a transmission line is infinity; the line isterminated in
- a short circuit
- an open circuit
- a complex impedance
- pure reactance
Q18 | Major advantage of a quarter wave transformer is
- proper matching
- high gain
- broader band width
- none of the above
Q19 | The reactances associated with the transmission line due to discontinuities:
- can be ignored
- have to be matched
- discontinuities do no exist
- none of the above
Q20 | The wave impedance of air for a wave propagating in it is
- 377 Ω
- 345 Ω
- insufficient data
- none of the above
Q21 | A loss less line of characteristic impedance Z0 is terminated in pure reactance of -jZ0 value. VSWR is
- 10
- 2
- 1
- infinity
Q22 | A rectangular air – filled waveguide has a cross section of 4 × 10 Theminimum frequency which can propagation in the waveguide is
- 1.5 ghz
- 2.5 ghz
- 2.0 ghz
- 3.0 ghz
Q23 | Indicate which one of the following modes do not exist in a rectangularresonantcavity
- te110
- tm110
- te011
- mt111
Q24 | The phase velocity of waves propagation in hollow metal waveguide is
- greater than velocity of light in free space
- less than velocity of light in free space
- equal to velocity of light in free space
- equal to group velocity
Q25 | The dominant mode in a rectangular waveguide is TE10 because this mode has
- no attenuation
- no cut off
- no magnetic field component
- the highest cut off wavelength