KCET2019PhysicsCommunication System
An antenna uses electromagnetic waves of frequency ( 5 MHz ). For proper working, the size of the antenna should be :
Options
- A( 15 ~km )
- B( 15 ~m )
- C( 3 ~km )
- D( 300 ~m )
Correct answer
B. ( 15 ~m )
Step-by-step solution
(B) ( C= f ) ( = C f = 3 10⁸ 5 10⁶ = 3 5 10²=60 ~m ) The antenna length should be ( 4 = 60 4 =15 ~m )