148.  Standard mismatching in microwave circuits have SWR from
A.0.5 : 1 to 2 : 1
B.1 : 0.5 to 2 : 1
C.1.2 :1 to2: 1
D.1.33 : lto2 : 1

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149. Magic tee is a combination of
A. two Hs and one E plane tee
B. two Hs and one plane tee
C. one H and two E plane tees
D. none of the above

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150.  When electromagnetic waves are reflected at an angle from a wall their wavelength along the wall is
A. the same as in free space
B. the same as the wavelength perpendicular to the wall
C. shortened because of the Doppler effect
D. greater than in the actual direction of propagation

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151. A signal propagated in a waveguide has a full wave of electric intensity change between the two further walls and no component of the electric filed in the direction of propagation. The mode is
A. TE1,
B. TEI, 0
C. TM2, 3
D. TE2, 0

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152. Which of the following diode is different from the remaining?
A. Backward diode
B. Hot carrier diode
C.ESbAR diode
D. Schottky carrier diode

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153. The efficiency of an ideal klystron is closer to
A.25%
B.50%
C.75%
D.90%

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154. For a rectangular waveguide with a = 2 cm and b = 1 cm, the cut-off wavelength for (TE10) mode would be
A. 2 cm
B. 1 cm
C. 4 cm
D. none of these

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