(1/focal length in meters) is equal to

A magnifying glass which is used to produce magnified images of small objects have

The iris has an opening at its center which is called

The vertex of spherical mirror lies on

The light rays traveling parallel to the principal axis of a convex lens after refraction meet at a point on the principal axis which is called

A material whose at least one side is curved is called

For a converging lens, the focal length is

If the focal length of a lens is expressed in meters then 1 Diopter is equal to

If a ray of light enters from air into glass, the angle of incidence formed is 30° and the refractive index of glass is 1.52, then the angle of refraction should be

The ratio of sin (x°) of the angle of incidence to sin (x°) of the angle of refraction is

A boy 1.8 m tall is standing 2.8 m in front of a camera which is using a convex lens having a focal length of 0.04 m. The image distance should be

The iris controls

The bending of light as it passes from one medium to another is called

The angle of incidence that causes the refracted ray in the rare medium to bend through 90° is called

The astronomical telescope, as is used to see distant

The size of the pupil is controlled by

The ratio of the sine of the angle of incidence 'i’ to the sine of the angle of refraction 'r’ is always equal to

The lens which is thick at center and thin at edges is

In-camera the distance between lens and film is fixed and is equal to

If a ray is traveling from denser to rare medium then increasing the angle of incidence

For a convex mirror, the focus lies

The distance between the optical center and the principal focus is known as

The maximum distance of a distant object from the eye on which the fully relaxed eye can focus is called

An optical instrument which is used to observe distant objects using lenses or mirrors is known as

The reflection by the smooth surfaces is called

The condition in which image is formed in front of the retina is called

If an object is far from the eye, the deviation of light through the lens must be

If the refractive index of water is 1.33 and of air is 1, the value of critical angle for water at 90° refracted angle should be

In a compound microscope, the objective lens has

The study of light behavior is called