11. Indicate the false statement, the parabolic reflector is :
(a) Omni-directional antenna
(b) Pencil beam antenna
(c) Popularly used antenna is terrestrial line-of- sight communication
(d) Not a broadcast antenna
12. The normal fade margin in a line-of-sight microwave system is :
(a) 10 db
(b) 25 db
(c) 40 db
(d) 60 db
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