The Sensex at the Bombay Stock Exchange plunged 298 points, or 1.5 percent, to close at a nearly two-month low of 19,143, as the rupee hit a fresh low against the dollar, and as global markets lost ground on thusday. The Nifty at the National Stock Exchange dropped 89 points, or 1.5 percent, to 5,789.Stock markets in Japan, Hong Kong, South Korea and Singapore declined between 0.5 percent and 1.5 percent.