Radiation And Microwave Techniques Set 3

On This Page

This set of Radiation and Microwave Techniques Multiple Choice Questions & Answers (MCQs) focuses on Radiation And Microwave Techniques Set 3

Q1 | For dominant mode propagation in TE mode, if the rectangular waveguide has a broaderdimension of 31.14 mm , then the cutoff wave number:
  • 100
  • 500
  • 50
  • 1000
Q2 | The klystron tube used in a klystron amplifier is a _________ type beam amplifier.
  • linear beam
  • crossed field
  • parallel field
  • none of the mentioned
Q3 | A PIN diode consists of ______number of semiconductor layers.
  • three
  • two
  • four
  • one
Q4 | The resistance of the PIN diode with positive bias voltage:
  • increases
  • decreases
  • remains constant
  • insufficient data
Q5 | Microstrip line can support a pure TEM wave.
  • true
  • false
  • microstrip supports only tm mode
  • microstrip supports only te mode
Q6 | The effective dielectric constant ∈r for a microstrip line:
  • varies with frequency
  • independent of frequency
  • it is a constant for a certain material
  • depends on the material used to make microstrip
Q7 | The arcs of circles on smith chart represent
  • normalised resistance or conductance
  • different values of swr
  • normalised reactance or susceptance
  • none of the above
Q8 | The characteristic impedance of a transmission line is
  • directly proportional to its length
  • inversely proportional to its length
  • independent of its length
  • none of the above
Q9 | Standing wave ratio (SWR) equal to unity implies that
  • the transmission line is open circuited
  • the transmission line is short circuited
  • the transmission line\s characteristic impedance equals load impedance
  • none of the above
Q10 | ), The normalised load impedance is
  • (1 + j 2)
  • (2500 + j 5000)
  • (0.5 +j)
  • none of the above
Q11 | V and a conduction current of 1.2A is
  • 25.2
  • 22.8
  • 28.8
  • 20
Q12 | and 9 respectively is
  • 25
  • 1.33
  • 7
  • 0.75
Q13 | Input impedance of a shorted lossless line of length π/4 is
  • zero
  • infinity
  • zo
  • none of the above
Q14 | V. The SWR is
  • 0.67
  • 1.2
  • 1
  • 1.5
Q15 | The reflection coefficient on a transmission line is 1/3, what is the SWR
  • 0
  • 3
  • 2
  • 4
Q16 | pF/m and an inductance of 75 nH/m
  • 5 ohm
  • 50 ohm
  • 500 ohm
  • 5000 ohm
Q17 | The wavelength of a line with a phase constant of 3.14 units is
  • 2
  • 1
  • 0.5
  • 3.14
Q18 | The dominant mode for rectangular waveguide is
  • te11
  • tm11
  • te10
  • tm10
Q19 | Following waveguide component not easily adjustable for tuning
  • stub
  • iris
  • screw
  • plunger
Q20 | What is the wavelength of a wave in a waveguide?
  • greater than in free space
  • depends only on the waveguide dimensions and the free-space wavelength
  • inversely proportional to the phase velocity
  • inversely proportional to the group velocity
Q21 | What is the cut-off frequency of a waveguide?
  • the highest frequency the waveguide operates
  • the lowest frequency the waveguide operates
  • the same as the operating frequency
  • the only frequency the waveguide operates
Q22 | For reduction in cross sectional dimension, waveguide to use is
  • ridged
  • circular
  • rectangular
  • flexible
Q23 | Out of following list, is not directional coupler
  • bathe hole
  • two hole
  • rate race
  • magic hole
Q24 | The condition which will satisfy the dimensions of the waveguide is
  • a = b
  • a>b
  • a
  • ab=0
Q25 | Materials generally preferred for wave guides are
  • brass and aluminium
  • cast iron and steel
  • non-metallic solids including plastics
  • all of the above