Math Chapter Wise Conic Section English MCQ PGT 2005 Q.The line lx+my+n = 0 is a normal to the ellipse 2 2 x y 1 a b + = + = is: A() 2 2 2 2 2 2 a b m n + + = l B() 2 2 2 2 2 2 a b m n − + = l C() 2 2 2 2 2 2 a b m n − + = l DNone of these Show answer Correct answer: () 2 2 2 2 2 2 a b m n − + = l