22. Broadcasting antennas are generally type
A. horizontal
B. vertical
C. either of the above
D. none of the above
23. Parabolic and lens antennas are extensively used for
A. shortwaves
B. microwaves
C. medium frequency waves
D. all of the above
24. The television receiver antennas are usually
A. parabolic dish type
B. helical antennas
C. dipoles
D. none of the above
25. The radiation pattern of parabolic antenna is
A. a figure of eight
B. highly directional
C. omni-directional
D. none of the above
26. The radiation pattern of loop antenna is
A. cardiod
B. circle
C. semi-circle
D. none of the above
27. A helical antenna produces radiation which is
A. circularly-polarised
B. omni-directional
C. either of the above
D. none of the above
28. Regarding Yagi-uda antenna which of the following statements is incorrect?
A. It has a folded dipole as the driven element
B. It has extremely high gain
C. It is often employed as VHF television receiving antenna
D. It is an array consisting of a driven element and parasitic elements arranged collinearly and closely
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