Rabat

Rabat (Arabic: ar-Ribaaṭ الرباط‎; Berber: ⴰⵕⴱⴰⵟ Aṛbaṭ) is the capital of Morocco and its seventh largest city center with an urban population of approximately 580,000 (2014) and a metropolitan population of over 1.2 million. It is also the capital of the Rabat-Salé-Kénitra administrative region.

The city is located on the Atlantic Ocean at the mouth of the river Bou Regreg. On the facing shore of the river lies Salé, the city's main commuter town. Rabat, Temara, and Salé form a conurbation of over 1.8 million people. Silt-related problems have diminished Rabat's role as a port; however, Rabat and Salé still maintain important textile, food processing and construction industries. In addition, tourism and the presence of all foreign embassies in Morocco serve to make Rabat one of the most important cities in the country.

Once a reputed corsair haven, Rabat served as one of the many ports in North Africa for the Barbary pirates, who were particularly active from the 16th through the 18th centuries.

Radio

Radio is the use of radio waves is to carry information, such as sound, by systematically modulating some property of electromagnetic energy waves transmitted through space, such as their amplitude, frequency, phase, or pulse width. When radio waves strike an electrical conductor, the oscillating fields induce an alternating current in the conductor. The information in the waves can be extracted and transformed back into its original form.

Radio systems need a transmitter to modulate (change) some property of the energy produced to impress a signal on it, for example using amplitude modulation or angle modulation (which can be frequency modulation or phase modulation). Radio systems also need an antenna to convert electric currents into radio waves, and vice versa. An antenna can be used for both transmitting and receiving. The electrical resonance of tuned circuits in radios allow individual stations to be selected. The electromagnetic wave is intercepted by a tuned receiving antenna. A radio receiver receives its input from an antenna and converts it into a form usable for the consumer, such as sound, pictures, digital data, measurement values, navigational positions, etc. Radio frequencies occupy the range from a 3 kHz to 300 GHz, although commercially important uses of radio use only a small part of this spectrum.