context: In 1893, George Westinghouse won the bid to light the 1893 World's Columbian Exposition in Chicago with alternating current, beating out a General Electric bid by one million dollars. This World's Fair devoted a building to electrical exhibits. It was a key event in the history of AC power, as Westinghouse demonstrated the safety, reliability, and efficiency of a fully integrated alternating current system to the American public. At the Columbian Exposition, under a banner announcing the "Tesla Polyphase System", Tesla demonstrated a series of electrical effects previously performed throughout America and Europe,:76 included using high-voltage, high-frequency alternating current to light a wireless gas-discharge lamp.:79 An observer noted:
question: বিশ্ব মেলায় ওয়েস্টিংহাউস এবং টেসলা কি ধরনের শক্তি প্রদর্শন করেছিল?
answers: AC power alternating current AC power