Category Science

HOW DOES A CASSETTE TAPE RECORD AND PLAY?

Discs were the main method of recording and playing music for the first half of the twentieth century, but sound recording on steel tape was used in the 1930s by radio stations. In 1935, two German companies developed a strong plastic tape, which had a layer of iron oxide on the surface. This invention eventually made it possible for smaller, domestic tape recorders to come into use. In 1963, Philips introduced something they called a “compact cassette”, which contained a thin tape within a plastic case. This was much lighter and more convenient for home use.

A cassette tape, tape cassette, or only cassette – is a rectangular and flat container that helps record & play audio and video. The original cassette tape only recorded audio, and that was enough. Usually, cassette tapes are made of plastic. But some models come with metal constructions. Cassettes have the sole purpose of transporting the magnetic tape. This is where the data comes from (sound & video signals).

These cassettes can be inserted in a recorder, so they can be used to record audio and/or video directly. And without having to handle the tape by hand – the cassette will do it automatically. When the cassette is put inside a player, then the magnetic tape will do its job to provide the audio or video from its small guides on tape. In short, a cassette tape allows users to transfer data around in magnetic tape – conveniently.

Magnetic Tape

On blank magnetic tape, the magnetized particles are all facing in the same direction. Electrical signals created by recorded sounds because the magnetized particles to move into patterns that match the sound signal. When the tape is played, the head “reads” the magnetized particles and creates electrical signals to match them, which are relayed to a loudspeaker to be played. In order to wipe the recording from the tape, all that needs to happen is for the tape to be passed through a strong magnetic field, which lines up the magnetized particles once more.

Magnetic recording, method of preserving sounds, pictures, and data in the form of electrical signals through the selective magnetization of portions of a magnetic material. The principle of magnetic recording was first demonstrated by the Danish engineer Valdemar Poulsen in 1900, when he introduced a machine called the telegraphone that recorded speech magnetically on steel wire.

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WHAT WAS THE EARLIEST SOUND RECORDING?

In 1877, the American inventor Thomas Edison (1847-1931) experimented with a machine called a “phonograph”, which converted sound vibrations into grooves on a cylinder covered with tinfoil. A sharp needle, called a stylus, was attached to a diaphragm at the narrow end of a large horn. When sound waves travelled into the horn, they made the diaphragm vibrate, causing the needle to move up and down, and cutting a groove of varying depth in the tinfoil. If this process was reversed, so that the needle was made to run over the grooves, it caused the diaphragm to vibrate. Vibrations passed through the horn, pushing air in front of them, to reach the listener’s ear as sound. Later, wax-coated cylinders were used instead of tinfoil, to give a better result.

The history of sound recording – which has progressed in waves, driven by the invention and commercial introduction of new technologies — can be roughly divided into four main periods:

  • the “Acoustic” era, 1877 to 1925
  • the “Electrical” era, 1925 to 1945
  • the “Magnetic” era, 1945 to 1975
  • The “Digital” era, 1975 to the present day.

Experiments of capturing sound on a recording medium for preservation and reproduction began in earnest during the Industrial Revolution of the 1800s. Many pioneering attempts to record and reproduce sound were made during the latter half of the 19th century – notably Scott’s Phonautograph of 1857 – and these efforts culminated in the invention of the phonograph by Thomos Edison in 1877. Digital recording emerged in the late 20th century and has since flourished with the popularity of digital music and online streaming services.

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HOW CAN RADIOS HELP NATURALISTS?

By putting collars with radio transmitters onto wild animals, naturalists have been able to track their movements, night and day, adding enormously to our knowledge of animal behaviour. The collars do not interfere with the animals’ normal lives. As well as learning about animal migrations and hunting patterns, naturalists are also able to discover more about the life span of animals in the wild, which may differ enormously from that of those kept in zoos and wildlife parks.

Since a protracted durable the tightlipped animals are studied by man, creating use of the many a method. Of course, within the starting it had been the employment of the fundamental explanation that helped them study animals. Folks would watch them, follow their tracks, creating interpretations etc. Those were the times of the co–existence for man and animal. The diversity of the kingdom is exploited so as that each little and enormous animals is tracked and monitored victimization constant system. Application of geoinformatics (remote sensing, Geographic system (GIS) associate degreed GPS) has enjoying an progressively vital role in conservation biology and life management by providing means that for grouping point and habitats data of life. Another advantage of the system is that the facility to integrate non–spatial knowledge directly, purpose knowledge collected from the sphere, GPS knowledge of life observance, pugmarks, scats, pellets etc. are fed directly and might generate a separate layer. But the trendy research goes on the far side the radio signals. It helps researchers to urge additional precise answers to the targeted queries concerning environs, migration patterns among others. And these answers are quantitative and analytical. Also, the advancement in technology has helped scientists to try to analysis victimization additional non–invasive means that and besides create the invasive ways safer. Each time a GPS radio collars tries to record a location it records data on the date, time and latitude. This data is then utilized to calculate the gap between locations, travel speed, location methods, direction, daily activity levels, home ranges, and analysis of spatial and temporal variations in behavior.

Recent technologies have helped solve the matter of untamed life following. Some electronic tags provide off signals that are picked up by radio devices or satellites whereas alternative electronic tags may embody deposit tags. Scientists will track the movement and locations of the labeled animals. These electronic tags will offer a good deal of information. Also, owing to their size and weight, electronic tags could produce drag on some animals, fastness them down. However, they’re costlier than the low–tech tags that are not electronic.

Tracking an animal by radio involves 2 devices. A VHF receiver picks up the signal, a bit like a home radio picks up a station’s signal. The receiver is sometimes during a truck, an ATV, or an airplane. To stay track of the signal, the soul follows the animal victimization the receiver. A transmitter attached to the animals sends out a proof within the type of radio waves, even as a radio station does. A soul would possibly place the transmitter around associate degree animal’s ankle, neck, wing, carapace, or dorsal fin. This approach of victimization radio following is accustomed track the animal manually however is additionally used once animals are equipped with alternative payloads.

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HOW DOES A VIDEO RECORDER WORK?

A video recorder stores television sound and pictures on a magnetic tape. It receives the electric signal that comes through a cable or aerial into the machine, then records it on tape in much the same way as a tape recorder does, although the video recorder makes diagonal tracks so that more information can be held on the tape. A record – replay head in the video recorder enables the information on tape to be sent to a television set.

Video tape recorder, also called Video Recorder, electromechanical device that records and reproduces an electronic signal containing audio and video information onto and from magnetic tape. It is commonly used for recording television productions that are intended for rebroadcasting to mass audiences. There are two types of video tape units: the transverse, or quad, and the helical.

The transverse unit uses four heads rotating on an axis perpendicular to the direction of 2-inch (5-centimetre) tape. The transverse format achieves a 1,500-inch-per-minute head-to-tape speed necessary for high picture quality. For broadcast industry needs, an audio track, control track, and cue track are added longitudinally. These units follow the standards of the North American Television Standards Commission—i.e., the electron beam sweeps 525 horizontal lines at 60 cycles per second.

The helical unit, designed for home and amateur use, uses half- or three-quarter-inch tape traveling around a drum in the form of a helix. There are various forms of these recorders: the playback deck can play back recorded programs but cannot record or erase; the video-record deck can record directly from a camera but cannot record off-the-air programs; the TV-record deck has an antenna and tuner for recording off-the-air programs. Portable reel-to-reel or cassette recorders are also produced.

Videotape has many uses in sport. For example, it may be used for an “action replay”, to check what really happened in a fast-moving sport. Athletes are also able to study videotape in order to see where they are making errors and so improve their technique.

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HOW DOES A TELEVISION SHOW PICTURES?

Television technology uses electric signals through cables or ultra-high frequency (UHF) radio waves to transmit pictures and sound to a television set, which acts as a receiver. The signals come into the television through a cable or an aerial. The picture signals are divided into three — one each for red, green and blue. In the television, there is an electron gun for each colour, which fires electron beams (also known as cathode rays) onto the screen. The screen is covered with chemicals called phosphors. The electron beams scan rapidly across the screen, causing tiny dots of phosphors to glow red, green and blue. Viewed with normal vision, from a distance, the dots blur into a full-colour picture.

Most people spend hours each day watching programming on their TV set, however, many people might wonder how in fact television works. There are many parts to this process and many technologies that are involved. Following are the most important processes and technologies involved in making television work.

Main Elements of the TV Process

There are many major elements that are required in order for TV to work. They usually include a video source, an audio source, a transmitter, a receiver, a display device, and a sound device.

Video Source

The video source is the image or program. It can be a TV show, news program, live feed or movie. Usually the video source has already been recorded by a camera.How TV Works?

Audio Source

Besides the video source, we also need the audio source. Practically all movies, TV shows and news programs have some sought of audio. Audio source can be in the form of mono, stereo or digitally processed to be later played back with surround sound.

Transmitter

The transmitter is necessary for broadcast television companies that broadcast a free signal to viewers in their area. The transmitter transmits both the video and audio signals over the air waves. Both audio and video signals are electrical in nature and are transformed into radio waves which can then be picked up by receivers (your TV set). A transmitter not only transmits one channels audio or video signal, but in most cases many different channels.

Receiver (TV set)

A receiver is usually integrated in your TV set and this receiver is able to grab radio waves (the transmitted signal) and process these radio waves back to audio and video electric signals that can now be played on your TV set.

Display Device

A display device is usually a TV set, but can also be just a monitor. The display device is able to receive electrical signals (usually sent from the receiver) and turn these electrical signals to a viewable image. Most standard TV sets incorporate a cathode ray tube (CRT), however new display devices can include LCD (liquid crystal display) and Plasma (gas charged display) display devices among others.

Sound Device

While most sound devices are built into your TV set in the form of speakers. Audio signals are obviously needed to match up with the video being shown to the viewer. Many newer TV sets have outputs to send the TV sound to high quality speakers that reproduce sound much better. Since audio signals can include surround sound technology, the TV set is able to send audio signals to the proper speakers located around your room.

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WHAT ARE TELECOMMUNICATIONS?

Telecommunications include sending and receiving messages by radio, television, telephone and fax. They began when the telegraph used electrical pulses, sent down a wire, to send information. Radio waves, electricity, or light can carry telecommunications. As well as a method of carrying the message, telecommunications also require a transmitter, to send the signals, and a receiver.

Telecommunications refers to the exchange of information by electronic and electrical means over a significant distance. A complete telecommunication arrangement is made up of two or more stations equipped with transmitter and receiver devices. A single co-arrangement of transmitters and receivers, called a transceiver, may also be used in many telecommunication stations.

Telecommunications devices include telephones, telegraph, radio, microwave communication arrangements, fiber optics, satellites and the Internet.

Telecommunications is also known as telecom.

Telecommunications is a universal term that is used for a vast range of information-transmitting technologies such as mobile phones, land lines, VoIP and broadcast networks.

In telecommunications, data is transmitted in the form of electrical signals known as carrier waves, which are modulated into analog or digital signals for transmitting information. Analog modulation such as that used in radio broadcasting is an amplitude modulation. Digital modulation is just an updated form of this.

Telecommunications and broadcasting are administered worldwide by an agency of the United Nations called the International Telecommunication Union (ITU). Most countries have their own agencies for enforcing telecommunications regulations.

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