What is the focal length if plane surface is silvered in previous illustration.

A planoconvex len becomes an optical system of 28 cm focal length when its plane surface is silvered illuminated from left to right as shown in Fig-A. It the same lens is instead silvered on the curved surface and illuminated from other side as in Fig.B, it acts like an optical system of focal length 10 cm. The refractive index of the material of lens is :

The convex side of a thin concavo-convex lens of glass of refractive index 1.5 has a radius of curvature of 20cm. The concave surface has a radius of curvature of 60cm. What is the focal length of the lens? The convex side is silvered and placed on a horizontal surface. What is the effective focal length of the silvered lens? The concave part is filled with water with refractive index 1.33. What is the effective focal length of the combined glass and water lens? If the convex side is silvered what is the new effective focal length of the silvered compound lens?

Focal length of a concave mirror is

A plano convex lens has focal length f = 20 cm . If its plane surface is silvered, then new focal length will be

An object is placed at a distance of 20cm from a equi-concave lens of focal length 30cm , whose one surface is silvered. If the radius of curvature of the silvered surface is 60cm , find the position and nature of the image.

What is the percentage of silver in German silver'?

Focal length of the plano-convex lens is 15cm. A small object is placed at A as shown in figure. The plane surface is silvered. The image will form at

What is the focal length of a concave mirror of radius of curvature 16.0 cm?