Radio, Torch, and an Umbrella

As a kid, I used to have a radio, torch, and umbrella. Honestly, I was not a big fan of the latter two but radio. Besides other inventions from the past, the radio surprised me. I learned later in college how it works.

Note that this post is purely written out of my memory. Errors are possible in the description of the radio.

The main channels are frequency-modulated (FM) and amplitude-modulated (AM). It has short-wavelength and long-wavelength channels. The units are written in the units of Hz and meter or kilometer. When you multiply the two numbers it precisely returns the speed of light. Here we learn radio waves are nothing but electromagnetic (EM) waves.

The EM waves come in a spectrum which goes as

Gamma rays->X-rays->untravoilet-> visible-> infrared->microwave->radio waves

From left to right are highly energetic. As you go from left to right, energy (frequency) decreases and wavelength increases. The following equations are at play

c = λ ν. Here c is the speed of light, λ is the wavelength, and ν is the frequency. E = m c² which is the equation of a photon together with E = h ν .

For radio to work, a station is needed that sends the radio wave and an antenna that receives the wave. The main ingredient of radio is a transistor. Radio converts The EM waves to sound waves as energy can neither be created nor destroyed but is interconverted.