A rod of length 2 cm makes an angle 3 principal axis of a thin convex lens. The lens has a focal length of 10 cm and is placed at a distance of 40 cm from the object as shown in the figure, The 3 -rad with the height of the image is 30-3 and the angle made by it 13 with respect to the principal axis is a rad. The value of a is rad, where n is n 3 2 40 3 cm 30-3 13 -cm a