Light - Reflection and Refraction

Flashcards for key concepts in the chapter on Reflection and Refraction of Light.

If an opaque object on the path of light becomes very small, light has a tendency to __.

Light bends around it, deviating from a straight line.

The angle of incidence is equal to the __.

Angle of reflection.

Image formed by a plane mirror is always __.

Virtual and erect.

A concave mirror is a spherical mirror whose reflecting surface __.

Faces towards the center of the sphere.

A convex mirror is a spherical mirror whose reflecting surface is __.

Curved outwards.

The center of the reflecting surface of a spherical mirror is a point called the __.

Pole.

The reflecting surface of a spherical mirror forms a part of a sphere, and the center of this sphere is called the __.

Center of curvature.

The radius of the sphere of which the reflecting surface of a spherical mirror forms a part is called the __.

Radius of curvature.

A straight line passing through the pole and the center of curvature of a spherical mirror is called the __.

Principal axis.

The point where rays parallel to the principal axis converge after reflection from a concave mirror is called the __.

Principal focus.

The distance between the pole and the principal focus of a spherical mirror is called the __.

Focal length.

The diameter of the reflecting surface of a spherical mirror is called its __.

Aperture.

The relationship between the radius of curvature (R) and focal length (f) of a spherical mirror is __.

R = 2f.

Convex mirrors always give an __ image.

Virtual and erect.

In a spherical mirror, the distance of the object from its pole is called the __.

Object distance.

The distance of the image from the pole of the mirror is called the __.

Image distance.

Magnification produced by a spherical mirror is given by the formula __.

m = h′/h.

The phenomenon of change in the direction of propagation of light when it travels from one medium to another is known as __.

Refraction of light.

The law stating that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant is known as __.

Snell's law of refraction.

The absolute refractive index of a medium is given by the formula __.

nm = c/v.

The ability of a medium to refract light is also expressed in terms of its __.

Optical density.

A lens that converges light rays is called a __.

Convex lens.

A lens that diverges light rays is called a __.

Concave lens.

The central point of a lens is its __.

Optical center.

The power of a lens is defined as __.

P = 1/f.

The SI unit of power of a lens is __.

Dioptre.