the radio
The changing electric field results in a changing magnetic field, and vice versa, and this is what causes the emergence of electromagnetic waves that work to transfer sound or information from one place to another, and this is a simple explanation of what the two scientists Faraday and Maxwell discovered, the discoverers of the theory of electromagnetism. On this basis, scientists and researchers conducted experiments to transmit sound from one place to another through magnetic waves, which led to the discovery of the radio “broadcast” in 1889 by the scientist Henry Hertz, where he worked on making a device that generates electromagnetic waves by generating an electrical discharge. He made an oscilloscope, a device that can receive electromagnetic waves and convert them into electricity.
The scientist Nikola Tesla developed the idea of an oscilloscope in 1896 until he made the first radio in the world, which receives electromagnetic waves, which carry sound as information transmitted in the air into electrical signals, which we can hear through simple circuits and headphones that convert the vibrational electrical energy into audible sounds.
radio industry
Tools
Do you need the following parts to build your radio:
- Long copper wire.
- A clean razor.
- pins.
- Pencils.
- Tissue Roll “The cylinder made of cardboard at the heart of the tissue paper.”
- A piece of wood 30 x 30 cm.
- Crystal headset.
The method of work
- Wrap 120 turns of copper wire around the tissue roll, making sure that the rolls are close to each other, and not too far apart.
- Fix the cardboard cylinder on the piece of wood horizontally, and secure the copper ends using staples.
- Place the razor blade at a distance of 10 cm from the cardboard cylinder and make sure that it is parallel to it.
- Attach a copper wire to the inner piece of carbon of the pencil.
- Connect one of the speaker wires to the copper wire in the stylus.
- Connect the other end of the speaker to one of the coil wires.
- Connect one end of the razor blade to the other wire of the cardboard cylinder with a copper wire.
- From the area where the speaker wire meets the end of the cardboard cylinder wire, connect it to a legacy source “a water pipe, for example.”
- From the end between the razor blade and the cardboard, attach a long copper wire attached to the antenna or to the TV receiver.
How to operate the radio
- When the electromagnetic signals pass through the air near the radio antenna or the copper wire suspended in the air, a magnetic field is created around the wire that leads to the generation of electrical signals inside the wire, which are transmitted to the razor blade and then to the headphones that convert the electrical signals into sounds that can be heard.
- To change the frequency of the signals you want to hear, pass the pencil over the razor blade to notice a change in the sounds heard through the speakers.
