# Quick Answer: Who Gave Lens Formula?

## Who discovered lens formula?

DescartesFigure 78: A thin lens.

is the refractive index of the lens.

The above formula is usually called the lens-maker’s formula, and was discovered by Descartes.

Note that the lens-maker’s formula is only valid for a thin lens whose thickness is small compared to its focal length..

## What is the use of lens formula?

The lens formula is applicable to all situations with appropriate sign conventions. This lens formula is applicable to both the concave and convex lens. If the equation shows a negative image distance, then the image is a virtual image on the same side of the lens as the object.

## What is the best eyeglasses lens?

Looking at Lenses The two best-selling eyeglass lenses are the most basic ones: CR-39 and the polycarbonate, both plastic. (Few people now use glass, which is heavy and breakable.) If you have a single-vision prescription (glasses to see far away or close up), you can generally get by with CR-39 lenses.

## Which lens is used in plane mirror?

2) Concave Lens:MirrorLensIt reflects the light that falls on its surface.It refracts the light. Convex lens converges and concave lens diverges the light.It can be plane or spherical.It has two surfaces out of which one is curved inwards or outwards.3 more rows

## What is a mirror formula?

A mirror formula can be defined as the formula which gives the relationship between the distance of object ‘u’, the distance of image ‘v’, and the focal length of the mirror ‘f’.

## What is V in convex lens?

For focal length, f in lens is always taken as negative for concave and positive for convex. … And for image distance, V in lens it is taken as positive in Convex lens since image is formed on +X side. It is taken as negative in Concave lens since image is formed in -X side of the Cartesian.

## What is a lens Class 10?

Lens: A lens is a piece of a refracting medium bounded by two surfaces, at least one of which is a curved surface. The commonly used lenses are the spherical lenses, which have either both surfaces spherical or one spherical and the other a plane one. … It converges a parallel beam of light on refraction through it.

## What is the formula for lens?

What is the Lens Formula for Convex Lens? Ans. According to the convex lens equation, 1/f = 1/v + 1/u. It relates the focal length of a lens with the distance of an object placed in front of it and the image formed of that object.

## What does a tight lens do?

Tight, center framing that throws a defocused but readable background behind the subject, or off-center framing with the subject looking / gesturing / moving into the environment.

## What is a lens in literature?

A critical lens is a way of looking at a particular work of literature by focusing on style choices, plot devices, and character interactions and how they show a certain theme (the lens in question). It is a common literary analysis technique.

## What type of lens is a mirror?

The equations we used for mirrors all work for lenses. A convex lens acts a lot like a concave mirror. Both converge parallel rays to a focal point, have positive focal lengths, and form images with similar characteristics. A concave lens acts a lot like a convex mirror.

## Which material Cannot be used to make a lens?

clayGlass and water are transparent materials. There is a certain amount of plastic that is transparent so that the plastic can be used to make a lens, but the clay is an opaque substance so that the light can not be transmitted into it and the clay can not be used to create the lens.

## What are the 3 types of lenses?

5 Basic Types of Camera LensesMacro Lenses. This type of camera lens is used to create very close-up, macro photographs. … Telephoto Lenses. Telephoto lenses are a type of zoom lens with multiple focal points. … Wide Angle Lenses. … Standard Lenses. … Specialty Lenses.Nov 8, 2020

## Is a lens a mirror?

Key Differences Between Mirror and Lens A mirror is either plane or spherical. In contrast, a lens has two surfaces, at least one of which is curved inwards or outwards. As the light ray strikes the mirror, it reflects off the light in a different direction, resulting in the formation of an image.

## Is V negative in concave mirror?

Only U’s value is negative, while V and F are positive. Even in the last case of a concave mirror, when object is placed between the focal point and pole, it produces a virtual, erect and enlarged image behind the mirror.

## What is 1 f 1 v 1 u?

Therefore: h/f = h/u + h/v and so 1/f = 1/u + 1/v and the formula is proved. An object is placed in front of a converging lens and gives a real image with magnification 5; when the object is moved 6 cm along the axis of the lens a real image of magnification 2 is obtained. What is the focal length of the lens?

## What is C and F in mirror?

For concave mirrors, when the object is outside C, the image will be between C and F and the image will be inverted and diminished (smaller than the object). For concave mirrors, when the object is between C and F, the image will be beyond C and will be enlarged and inverted.

## What is the power of lens?

Power of lens is known as the inverse of the focal length of the lens measured in meter(m). S.I unit of power = Dioptre (D) Power of lense = 1/ focal length in meter.

## How were lenses first made?

Early Glasses The first wearable glasses known to history appeared in Italy during the 13th century. Primitive glass-blown lenses were set into wooden or leather frames (or occasionally, frames made from animal horn) and then held before the face or perched on the nose.

## What is V and U 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.

## What is the difference between the mirror formula and lens formula?

What is the difference between Real and Virtual Image?…Difference between Mirror and Lens.MirrorLensA mirror can be plane or spherical (concave or convex)A lens is usually curved from either one or both surfaces.Mirror formula is 1/f = 1/v + 1/uLena formula is 1/f = 1/v – 1/u2 more rows•Apr 27, 2020

## What is the mirror formula and lens formula?

In a spherical mirror: The distance between the object and the pole of the mirror is called the 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 pole of the mirror is called Focal Length(f).

## What is V and U in light?

Where v is the image distance and u is the object distance. Hence, the expression for magnification (m) becomes: m = h’/h = -v/u. Learn more about Reflection of Light here.