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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