Ray Optics and ...

A Plano convex lens of curvature of 30 cm &R.I. 1.5, produces a real image of an object kept 90cm from it. The magnification is

How will the image formed by a convex lens be affected if the central portion of the lens is wrapped in a black paper

An object is placed at a distance of 10 cm from a co-axial combination of two lenses A and B in contact. The combination forms a real image three times the size of the object. If lens B is concave with a focal length of 30 cm, what is the nature and focal length of lens A ?

A converging lens is used to form an image on a screen. When the upper half of the lens is covered by an opaque screen

Total internal reflection can take place only if light is travelling from

An equi-convex thin lens (μ =1.5) of focal length in air as 30cm is sealed into an opening in one end of tank filled with water ((μ =1.33). At the end of the tank opposite the lens is a plane mirror, 80 cm distant from the lens. The position of the image formed by the lens-water-mirror system of a small object outside the tank on the lens axis and 90cm to the left of the lens will be

Optical fibre communication uses the principle of

According to Cartesian sign convention.

When an astronomical telescope is focused on a distant star, the distance of the eye piece from the objective is 60 cm. When focused on a distant flag post the eye piece must be drawn at 0.1cm. If the focal length of the eye piece is 5cm; what will be the distance of the pole from the objective? Assume that the eye is focused for infinity?

The objective of a telescope has a focal length of 1.2 m. It is used to view a 10.0 m tall tower 2 km away. What is the height of the image of the tower formed by the objective?