99. A very lossy, m/1 long, 502 transmission line is open circuited at the load end. The input impedance measured at the other and of the line is approximately

A.0

B.50S2

C. oo

D. none of the above

100. In a homogeneous nonconducting region where P1r = 1, the value of Cr will be IGiven E = 30n. ejlmt- 4/301 a = 1.0e-i(mt- 4/331)1 ax (Aim)

A.16

B.8

C.4

D.32

101. A short grounded vertical antenna has a length / which is 0.05 at frequency f. If its radiation resistance at f is R ohms, then its radiation resistance at a frequency 2f will be

A. R/2 ohms

B. R ohms

C. 2R ohms

D. 4R ohms

102. Two isotropic radiators A and B are placed along the X-axis at the positions (-2t,/8, 0) and (+2t,/8, 0) respectively. The elements are fed by currents of equal amplitude with the phase of B leading that of A by 900? The array pattern will have maxima

A. in the direction of the + X axis

B. at an angle of 450 with respect to the + X axis

C. in the direction of + Y axis

D. in the direction - X axis

103. If a vertical dipole antenna is used in conjunction with a loop antenna for direction finding, then the field pattern obtained will be

A. linear

B. elliptical

C. left head circular right head circular

D.

104. A transmission line whose charactersistic is a resistance

A. must be a lossless line.

B. must be a distortionless line.

C. may not be a lossless line.

D. maynot be a distortionless line.

105. A loss less transmission line having 501 characteristic impedance and length A14 is short circuited at one end and connected to an ideal voltage source of IV at the other end. The current drawn from the voltage source is

A.0

B. 0.02 A

C.2A

D. none of the above

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