**Contents**show

## What is the focal length of 5D lens?

Find its focal length. As we know, the power of the lens is the reciprocal of its focal length. Hence, the focal length is **20 cm**.

## What is the focal length of convex lens having 5.0 D?

∴ Focal length = **20 cm**.

## What is the focal length of a concave lens with number?

The distance between the pole and the principal focus is called the focal length (f) of the lens. The given focal length of the concave lens is **f = -2 m**. It is negative because a concave lens always has a negative focal length.

## What is the focal length of a lens with 0.5 D?

It is. a concave lens of focal length **5 m**.

## What is the focal length of a lens if power is +5D?

Answer: The focal length of the lens is **20 cm**.

## Is the power of lens is +5D then its focal length will be?

Solution(By Examveda Team)

Power of a lens is determined by the formula P=1/f (when focal length is in meters) and P=100/f (when focal length is in centimeters) Here,the power is given as 5 diopters. On equating we get, ⇒5=100/f ⇒**f**=100/5 =20 cms.

## Is the power of convex lens is 5.0 D then its focal length is 50 cm?

it’s false statement that focal length of convex lens is 50cm . because focal length of convex lens is 20cm. we know, power of a lens **is reciprocal of its focal length**. … An object 5.0 cm in length is placed at a distance of 20cm in front of a convex mirror of radius of curvature 30cm.

## What is the focal length of convex lens whose power is 5 diopter?

Answer: The focal length of the lens is **20 cm**.

## What is the power and focal length of a convex lens?

The power of a lens is defined as **the reciprocal of the focal length**. Lens power is measured in dioptres (D). Converging (convex ) lenses have positive focal lengths, so they also have positive power values. Diverging (concave ) lenses have negative focal lengths, so they also have negative power values.

## What is the power of a concave lens of focal length 2 cm?

= **-50 dioptres**.

## Is focal length of concave lens positive or negative?

The focal length of a **concave surface is negative**, whereas the focal length of a convex surface is positive. Therefore, for a lens, the power of a concave and convex lens is negative and positive respectively.

## Is focal length of concave mirror positive?

The focal length f of a concave mirror **is positive**, since it is a converging mirror. Figure 2.