# In a plano-convex lens, the curved surface?

The surface of a plano-convex lens has **focusing effect on light**while a flat surface has no focusing or defocusing effects.

## When the curved surface of a plano-convex lens is silvered, how does it behave?

Tip: When one end of a plano-convex lens is silvered, it does **a mirror**. The light is reflected once on the silvered surface and refracted twice on the surface of the lens to form the final image.

## What is the radius of curvature of a plano-convex lens?

In a plano-convex lens, the radius of curvature R1=∞ on the plane side is equal to infinity. Because, the mirror needs to be part of a sphere, and to make it flat, the radius of the sphere must be infinite.The radius of curvature of the convex edge is **R2=−20cm** as stated in the question.

## What happens when a plano-convex lens is silvered?

Plano-convex lenses, when their planes are silvered, **Equivalent to a concave mirror with a focal length of 28 cm**. When its curved surface is silver-plated and the plane is not silver-plated, it is equivalent to a concave mirror with a focal length of 10cm, then the refractive index of the lens material is . One.

## What is a plano-convex lens?

Plano-convex lenses are **Positive focal length element with one sphere and one plane**. These lenses are designed for infinite conjugate (parallel light) use or simple imaging in non-critical applications. These optics are ideal for general purpose focusing elements.

## Q.30) Plano-convex lenses are perfectly suitable for plano-concave lenses.their planes are parallel

https://www.youtube.com/watch?v=s_Zcf18LMAE

**28 related questions found**

## How to tell if a flat mirror is a convex lens?

…two simple lenses, usually planoconvex (flat on one side, curved outward on the other, with curved surfaces facing each other).This type of magnifier is eyepiece based **Huygens telescope**, where lateral chromatic aberration is corrected by spacing the elements apart by the focal length. …

## Where are plano-convex lenses used?

Plano-convex lenses are the best choice **Focus parallel rays to a point**. They can be used to focus, collect and collimate light. The asymmetry of these lenses minimizes spherical aberration in situations where objects and images are at unequal distances from the lens.

## How do plano-convex lenses perform?

When a plano-convex lens is silvered on the flat side, it exhibits **Like a concave mirror with a focal length of 60cm**. However, when the convex surface is silver, it behaves like a concave mirror with a focal length of 20cm.

## Is the focal length of a concave mirror positive?

focal length f of a **Concave mirror is positive**, because it is a converging mirror. Figure 2. (a) Parallel rays reflected from a large spherical mirror do not all intersect at a common point. (b) If the spherical mirror is small compared to its radius of curvature, the parallel rays are focused to a common point.

## When the plane of a plano-concave lens is silvered?

If μ is the index of refraction and R is the radius of curvature of the surface, the system will behave like a mirror with concave curvature.

## Why use plano-convex lenses for Newton’s rings?

form alternating dark and light rings **Due to the presence of an air film** When a plano-convex lens is placed on a glass plate, it is called a Newton’s ring. When a flat-convex surface is placed on a glass plate, an air film of increasing thickness is formed.

## What is the principal axis of a convex lens?

The main axis is defined as **line through the two curvatures of the lens**. It can also be defined as the line connecting the two centers of the lens. The principal axis connecting the two centers in a convex lens is given below.

## What is the focal length of a convex lens with a radius of curvature of 20cm?

The radius of curvature is twice the value of the focal length of the spherical mirror. (The focal length is the point on the principal axis where rays from infinity parallel to the axis meet.) So, the answer is option (D); **40 cm**.

## What is the focal length of a concave mirror?

Focal length – **The distance from the pole P of the concave mirror to the focal point F** is the focal length of the concave mirror. Therefore, the focal length of a concave mirror can be estimated by taking a « true image » of a distant object at the focal point, as shown.

## When can a convex lens act as a diverging lens?

Condition: when a **A convex lens is placed in a liquid with an index of refraction greater than that of the lens material**which behaves like a diverging lens.

## What is the focal length of the surface?

The focal length of a lens depends on the refractive index and radius of curvature of the lens. The lens manufacturer formula is as follows: **1f=(μ−1)(1R1−1R2)** where f is the combined focal length, μ is the refractive index of the lens, and R1, R2 are the radii of the curved surfaces, respectively.

## Is the V of a convex lens positive?

‘**v’ is always positive for convex** Mirrors and concave lenses. The distance measured from the optical center to the right of the lens is considered +ve, and the t from the optical center to the left is considered -ve.

## Is the V of a concave lens positive?

A concave lens spreads light incident on it. …you can easily verify that the focal length is in the positive x direction for a convex lens, and in the negative x direction for a concave lens.So f is **positive** For convex lenses, negative for concave lenses. The reason is that the sign of v changes.

## Is the focal length of a convex lens positive?

The focal length is **positive** That is a convex lens. Then the focus is true or the light passes through that point. A negative sign indicates that the image is virtual or that the light does not pass through the image. A positive sign means the image is upright.

## What is the convex surface of Plano’s convex lens?

When silvered on the flat side, a Plano convex lens behaves like a **concave mirror** The focal length is 30 cm. When silvered on a convex surface, a Plano convex lens behaves like a concave mirror with a focal length of 10 cm. R is the radius of curvature cm. Therefore, the correct answer is option (D).

## What are the 3 uses of convex lenses?

- Convex lenses are used in microscopes and magnifying glasses to focus all incoming light to a specific point. …
- Convex lenses are used in cameras. …
- Convex lenses are used to correct farsightedness. …
- Converging lenses are also used in projectors.

## What is a plano-concave lens for?

Use plano-concave lenses **Expand the beam or increase the focal length of the optical system**. Bi-concave lenses are often used to expand a beam or increase the focal length in an optical system, often in combination with other lenses.

## Where is the focal point of a plano-convex lens?

Plano-convex focusing **Collimated beam to back focus** and collimates light from a point source.

## What is the difference between a convex lens and a plano-convex lens?

Plano-convex lenses have **a flat (planar) surface** A convex surface, a lenticular lens has two convex surfaces. Plano-convex lenses typically produce small spherical distortions when used in camera optics, telescopes, etc. that typically focus at infinity.

## What type of images do plano-convex lenses form?

A typical plano-convex lens (Figure 1(b)) has a positive convex surface and a flat (planar) surface on the opposite side of the lens.These lens elements focus parallel rays to a positive focus and form **Real images that can be projected or manipulated through spatial filters**.