The image of an object formed by a convex lens is of the same size as the object. If the image is formed at a distance of 40 cm, find the focal length of the lens. Also ,find the power of the lens. At what distance from the lens is the object placed?

When an eye is focussed on a distant object, the focal length of the eye lens is ..........

Shown an object and its image formed by a thin lens. Then the nature and focal length of lens is

For a thin convex lens when the heights of the object is double than its image, its object distance is equal to ....... Focal length of a lens is f.

If the focal length of objective lens is increased then magnifying power of ......

The human eye can focus on objects at different distances by adjusting the focal length of the eye lens. This is due to…

In a displacement method the distance between the object and the screen is 70 cm and the focal length of the lens is 16 cm, find the separations of the magnified and diminished image position of the lens.

An image of an object obtained by a convex mirror is n times smaller than the object. If the focal length of lens is f, the object distance would be ...........

The redius of curvature of the convex face of a plano-convex lens is 12cm and its refractive index is 1.5. a. Find the focal length of this lens. The plane surface of the lens is now silvered. b. At what distance form the lans will parallel rays incident on the convex face converge? c. Sketch the ray diagram to locate the image, when a point object is places on the axis 20cm from the lens. d. Calculate the image distance when the object is placed as in (c).

The image of an object, formed by a plano-convex lens at a distance of 8 m behind the lens, is real is one-third the size of the object. The wavelength of light inside the lens is 2/3 times the wavelength in free space. The radius of the curved surface of the lens is

The focal length of the lens in a photographic camera is 5cm. what is the power of the lens?