Equity benchmark indices Sensex and Nifty tumbled on Tuesday amid persistent foreign fund outflows and weak trend in Asian and European markets.Photograph: Hemanshi Kamani/ReutersThe 30-share BSE Sensex dropped 519.34 points, or 0.62 per cent, to settle at 83,459.15.During the day, it tanked 565.72 points, or 0.67 per cent, to 83,412.77. The 50-share NSE Nifty declined 165.70 points, or 0.64 per cent, to 25,597.65.From the Sensex firms, Power Grid, Eternal, Tata Motors, Tata Steel, Maruti and Bharat Electro ...