Question

The U.S. Navy has long proposed the construction of extremely low frequency (ELF waves) communications systems; such waves could penetrate the oceans to reach distant submarines. Calculate the length of a quarter-wavelength antenna for a transmitter generating ELF waves of frequency 77 Hz.

Answer 1

Answer:

length of a quarter wavelength antenna for transmitter elf waves are zero

Explanation:

Find the length of a quarter wavelength antenna for transmitter elf waves

Given information

frequency (ELF waves) → 77Hz

Speed of light → 3$\times$$10^8$m/s

$v=\lambda f-------------1$

where

$\lambda$ → wavelength of the antenna

f → frequency of the ELF waves

$v$ →  speed of light

so rewrite the equation in $\lambda$ from

$\lambda=\dfrac{v}{f}$

Substitute $3\times10^8m/s$ = $v$

Substitute 75Hz = f

$\lambda=\dfrac{3\times10^8m/s}{77Hz}$

$=3.9\times 10^6$m

since we get this value,but this size of antenna mount on submarine is not possible.

so $\lambda$ is zero