A convex lens of focal length 'F' produces a real image 'n' times the size of the object. The image distance is

A ray of light is incident at an angle $i$ on one face of a thin angled prism. The ray emerges normally from the other face. Refractive inder of the glass prims is $n$ and angle of prism is $A$. The value of $i$ is

An object is clearly seen through an astronomical telescope of length 50 cm . The focal lengths of its objective and eye-piece respectively, can be

By increasing the aperture of the objective lens, wavelength of light, focal length of the objective lens and the resolving power of an astronomical telescope respectively