The concave surface 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`.The covnex side is silvered and placed on a horizontal surface as shown in the figure.

The combination behaves like

The concave surface 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 .The covnex side is silvered and placed on a horizontal surface as shown in the figure. The focal length of the combibnation has the magnitude.

The concave surface 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 .The covnex side is silvered and placed on a horizontal surface as shown in the figure. A small object is placed on the principal axis of the combination,at a distance of 30cm in front of the mirror.The magnification of the image is

The convex surface of a thin concave-convex lens of glass of refractive index 1.5 has a radius of curvature 20 cm. The concave surface has a radius of curvature 60 cm. The convex side is silvered and placed on a horizontal surface as shown in figure. (a) Where should a pin be placed on the axis so that its image is formed at the same place ? (b) If the concave part is filled with water (mu = 4/3), find the distance through which the pin should be moved so that the image of the pin again coincides with the pin.

The convex surface of a thin concavo-convex lens of glass of R.l. 1.5 has a radius of curvature 20 cm. The concave surface has a radius of curvature 60 cm. The convex side is silvered and placed horizontally. Q Where should a pin be placed on the axis such that its image is formed on the same point.

The convex surface of a thin concavo-convex lens of glass of R.l. 1.5 has a radius of curvature 20 cm. The concave surface has a radius of curvature 60 cm. The convex side is silvered and placed horizontally. Q If the concave part is filled with water of refractive index 4/3, find the distance through which the pin should be moved so that the image of the pin again coincides with the pin?

A plano convex lens is made of glass of refractive index 1.5. The radius of curvature of its convex surface is R. Its focal length is