Question

A quarter-wave monopole radio antenna (also called a Marconi antenna) consists of a long conductor of one quarter the length of the transmitted wavelength. The lower end of the antenna is connected to a conducting ground plane (often simply the Earth) which reflects the transmitted signal, creating an effective antenna length of a half wavelength. (a) What must be the height of the antenna (in m) for a radio station broadcasting at 514 kHz

Answer 1

Answer:

145.91 m

Explanation:

Data provided in the the question:

Wavelength of radio wave, $\lambda = \frac c f$

Here, c is speed of radio wave in air = 3 × 10⁸ m/s

f is the frequency = 514 kHz = 514 × 10³ Hz

Thus,

Wavelength = (3 × 10⁸) ÷ (514 × 10³) m

or

Wavelength = 583.65 m

Thus,

The height of the antenna will be

= $\frac \lambda 4$ = 583.65 ÷ 4 m

= 145.91 m