Geometrical Optics

A rod of length 2‌cm makes an angle ‌

2π

3

‌rad with the principal axis of a thin convex lens. The lens has a focal length of 10‌cm and is placed at a distance of ‌

40

3

‌cm from the object as shown in the figure. The height of the image is ‌

30√3

13

‌cm and the angle made by it with respect to the principal axis is α rad. The value of α is ‌

π

n

rad, where n is