Ray Optics Test...

Focal length of a convex lens will be maximum for

A lens is placed between a source of light and a wall. It forms images of area A₁ and A₂ on the wall for its two different positions. The area of the source or light is

A combination of two thin lenses with focal lengths f₁ and f₂ respectively forms an image of distant object at distance 60 cm when lenses are in contact. The position of this image shifts by 30 cm towards the combination when two lenses are separated by 10 cm. The corresponding values of f₁ and f₂are

If the central portion of a convex lens is wrapped inblack paper as shown in the figure

A diminished image of an object is to be obtained on a screen 1.0 m from it. This can be achieved by appropriately placing

A convex lens forms a real image of a point object placed on its principal axis. If the upper half of the lens is painted black, the image will

In the figure, an air lens of radii of curvature 10 cm (R₁ = R₂ = 10 cm) is cut in a cylinder of glass (μ = 1.5). The focal length and the nature of the lens is

A lens (focal length 50 cm) forms the image of a distant object which subtends an angle of 1 milliradian at the lens. What is the size of the image

The focal length of a simple convex lens used as a magnifier is 10 cm. For the image to be formed at a distance of distinct vision (D = 25 cm), the object must be placed away from the lens at a distance of

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