**Contents**show

## Is U of convex lens positive or negative?

question_answer Answers(3) According to Cartesian sign convention, object distances **(u) are always negative** as the object is placed to the left of the mirror/lens. Focal length (f) is positive for a convex lens and convex mirror. Focal length is negative for concave lens and concave mirror.

## What is the sign of V in convex and concave lens?

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. In Concave mirror V is taken as positive and negative for convex mirror.

## What is the sign of UV and f in convex lens?

Note: According to sign-convention, u has negative value and v has positive value for convex les. Hence, **f comes positive**.

## How do you know if V is positive or negative?

In case of a concave lens ‘**v’ is always negative**. In case of convex lens it is negative or positive it depends on object distance n location.

## What is the sign convention for lens?

Sign convention is **a set of rules to set signs for image distance**, object distance, focal length, etc for mathematical analysis of image formation. According to it: Object is always placed to the left of lens. All distances are measured from the optical centre of the mirror.

## What is the sign of height of object in convex lens?

In the case of a convex mirror, always **an erect image is formed**, thus the height of image is taken as positive.

## What happens when light passes through a convex lens?

Convex lenses refract light inward toward a focal point. Light rays passing through the edges of a convex lens are bent most, whereas light passing through the **lens’s center remain straight**. Convex lenses are used to correct farsighted vision. Convex lenses are the only lenses that can form real images.

## What is U V f?

The equation connecting the distance between mirror and object (u), distance between mirror and image (v), and the focal length of the mirror (f) is called mirror formula.

## How do you know if a lens is concave or convex?

**A convex lens is thicker at the centre and thinner at the edges**. A concave lens is thicker at the edges and thinner at the centre. Due to the converging rays, it is called a converging lens. Due to the diverging rays, it is called a diverging lens.

## Why we take the value of U as negative in mirror formula?

because according **to sign convention distance is always measured from pole which is opposite to the direction of incident ray**. Hence distance of the object always negative in the mirror.

## When image is positive mirror will be?

If m has a magnitude greater than 1 the image is larger than the object, and an m with a magnitude less than 1 means the image is smaller than the object. If the magnification is positive, the **image is upright compared to the object**; if m is negative, the image is inverted compared to the object.