What does focal length mean?

The focal length of a lens is determined when the lens is focused at infinity. Lens focal length tells us the angle of view—how much of the scene will be captured—and the magnification—how large individual elements will be. The longer the focal length, the narrower the angle of view and the higher the magnification.

What is definition of focal length in class 10th?

The distance between the focus and the optical center is known as focal length. It is denoted by f. Focal length is equal to half the radius of the curvature i.e. f=r/2.

What is focal length in easy words?

Focal-length definition

(optics) The distance at which something (e.g. a lens, mirror etc.) is in focus; in air it is the distance along the optical axis from a “principal plane” of the lens to one of the lens’s focal points.

What is the focal length answer?

The distance between the convex lens or a concave mirror and the focal point of a lens or mirror is called the focal length. It is the point where parallel rays of light meet or converge.

What is focal length of plane mirror Class 10?

infinity
A plane mirror is a flat reflecting surface. Thus, in the case of a plane mirror, when the parallel rays of light strike the mirror they get reflected back parallel to each other. So, they never meet or we can say they meet at infinity. So, the focal length of the plane mirror is Infinity.

What is focal length with diagram?

Focus is defined as the point through which the reflected light rays pass (or appear to pass) when incident light rays are parallel to the principal axis. It is located at the midpoint of pole and centre of curvature. The distance between the pole and the focus of the mirror is called the focal length of the mirror.

What is focal length and focus?

Solution : Focus – The point on the principal axis at which the incident rays which are parallel to the principal axis, meet after reflection from the mirror is called focus. Focal length – The distance between focus and pole is focal length.

What is focal length Physics 12?

Focal length of a spherical lens is the distance between optical centre and focus of the lens. The Focal length of a lens is half of its radius of curvature. We usually denote the centre of curvature of a lens with the term 2Finstead of denoting it by C.

What is focal length and principal focus?

Principle focus : The principal focus of a convex lens is a point on its principal axis to which light rays parallel to the principal axis converge after passing through the lens. Focal length: The distance of the principle focus from the optical center of a lens is called its focal length .

What is Focus Point Class 10?

Solution : Focus – The point on the principal axis at which the incident rays which are parallel to the principal axis, meet after reflection from the mirror is called focus.

What is principal focus Class 10?

When the incident rays are parallel to the principal axis, they converge at a point after refraction. This point where the parallel set of incident rays meet at a point after refraction is called the principal focus of a convex lens.

What is focal length Brainly?

Focal length is the distance between the center of a convex lens or a concave mirror and the focal point of the lens or mirror — the point where parallel rays of light meet, or converge.

What is magnification in physics class 10?

Magnification is defined as the ratio of the height of image to the height of object. m=hiho.

What is mirror formula?

The relation between focal length of mirror, distance of the object and distance of the image is known as mirror formula. It is given by. u1+v1=f1.

What is optical centre?

Medical Definition of optical center

: a point on the axis of a lens that is so located that any ray of light passing through it in passing through the lens suffers no net deviation and that may be within, without, or on either surface of the lens.

What is mirror pole?

Pole of a mirror is the geometrical center of the spherical surface of the mirror. Principal axis is the straight line that joins the pole of the mirror to its center of curvature. Center of curvature of mirror is the center of the sphere of which the mirror is part of.

What is the unit of mirror?

In a spherical mirror:

The distance between the object and the pole of the mirror is called Object distance(u). The distance between the image and the pole of the mirror is called Image distance(v). The distance between the Principal focus and the pole of the mirror is called Focal Length(f).

What is called lens formula?

What is the Lens Formula? According to the Convex Lens equation, the Lens formula is 1/f = 1/v + 1/u. It relates the Focal Length of a Lens with the distance of an object which is placed in front of it and the image formed of that object. Lens magnification is defined as the ratio of the image Length and object Length.

What is image distance?

Image Distance, s’, is the distance from a lens or mirror to an image. • Magnification, m, is the amount of size increase (or decrease) of the image as compared to the object. m = hi /ho • Images are formed by lenses and mirrors where light rays cross or focus.

Who discovered mirror formula?

A discovery by the great German chemist Justus von Liebig in 1835 made mirrors widely available. Liebig found a way to coat glass with a thin layer of metallic silver by depositing the metal directly by means of a chemical reaction.

What is V in lens formula?

where u is the distance of the object from the lens; v is the distance of the image from the lens and f is the focal length, i.e., the distance of the focus from the lens. N.B. other sign conventions are sometimes used in the literature. = 2 6 − 1 6 = 1 6 So v = 6 cm.