Traveller's cheques and credit cards (American Express, Visa, Mastercard) are exchanged for Vietnamese dong at the banks. Cards can be used in travel agencies, hotels, and major restaurants. US currency is exchanged for Vietnamese dong and treasury notes in banks, exchange bureaus, hotels, and jewellery shops.
Nikola Tesla designed the first hydroelectric power plant at Niagara Falls, New York which started producing electrical power in 1895. This was the beginning of the electrification of the United States and the rest of the world. Today, Teslaâs AC electricity is lighting and powering the globe.
Tesla employed the Tesla coil in his efforts to achieve wireless power transmission, his lifelong dream. In the period 1891 to 1900 he used it to perform some of the first experiments in wireless power, transmitting radio frequency power across short distances by inductive coupling between coils of wire.