Question

The length of a dipole antenna for a carrier wave of frequency $6\times 10^8\text{Hz}$ is ( take speed of EM wave $3\times 10^{8}m{s}^{-1}$ )

• A. $0.25\text{m}$
• B. $1\text{m}$
• C. $2\text{m}$
• D. $0.1\text{m}$

Answer 1

Answer: (A)

Length of the antenna
$=\frac{\lambda }{2}=\frac{c}{2\upsilon }$
( Where $c$ = speed of light = $3\times 10^{8}m{s}^{-1}$ , $\upsilon$ = frequency = $6\times 10^{8}Hz$ )
putting these values in formula above
Length = $\frac{3\times 10^8}{2\times 6\times 10^8}=0.25m$