106. Transmission of power to a load over a transmission line achieves optimum value when standing-wave ratio (SWR) becomes

A. 2 : 1

B. 1 : 2

C. 1 : 1

D. 2 : 2

107. The input impedance of a loss-les transmission line is 100 ohms when terminated in a short-circuit, and 64 ohms when terminated in an open circuit. The characteristic impedance of the line is

A. 80 ohms

B. 164 ohms

C. 36 ohms

D. 64 ohms

108. The electric field at a point from a transmitter radiating a certain power is 2.5 mV/m. If the transmitter power is doubled, the field strength at that point will be about

A. 2.5 mV/m

B. 3.5 mV/m

C. 5 mV/m

D. 10 mV/m

109. A quarter-wave transformer is used for matching a load of 225 ohms connected to a transmission line of 256 ohms in order to reduce the SWR along the line to 1. The characteristic impedance (in ohms) of the transformer is

A.225

B.256

C.240

D.273

110. Which of the following conditions will not guarantee a distortionless transmission line?

A. R = G = 0

B. RC =GL

C. Very low frequency range (R>> c)L, G >> cuC)

D. Very high frequency range (R << taL, G <

111. On a resistively terminated high frequency loss-loss transmission line fed by a 500 MHz source, the VSWR is found to be equal to 2 and the first voltage minimum is measured at 30 cm from the load end. What is the value of the "normalised" load resistance?

A.3

B.2

C.1

D.4

112. For a quarter wavelength ideal transmission line of characteristic impedance 50 ohms and load impedance 100 ohms, the input impedance will be

A.25

B. 50 SI

C. 100 SI

D. 150 Q

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