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Hence in the above case it is given that the focal length is 40cm or 0.4m. So the power =- 1/0.4= -2.5D the sign is used to determine the type of lens used.

## What is the power of lens of focal length 40cm?

The correct answer is option 4, i.e. -2.5 D.

## What is the power of the combination of lenses of focal length 40 cm and 50 cm?

0.5 D is the power of the combined lenses.

## What is the power of concave lens of focal length 50cm?

= 100/50 = 2 dioptre.

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

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. The unit of power is dioptre (D) and 1D = 1m^{–}^{1}.

## What is the power of a lens calculate power of a concave lens of focal length 40 cm 2?

power of lens = 1/ focal length ( in meter) when focal length is 40 that mean it is positive so therefore the resulting power will also be positive. If the power is positive it considered as power of convex lens. power = 1/ 0.4 = 2.5 D. another focal length is -20..

## What is the power of a lens with focal length of 10cm?

Hence, the power of the lens is $10$ dioptre. Note:The power of a lens is measured in dioptre if and only if the focal length is in meter since diopter is a S.I unit.

## What is concave lens in physics?

A concave lens is a lens that possesses at least one surface that curves inwards. … It is a diverging lens, meaning that it spreads out light rays that have been refracted through it. A concave lens is thinner at its centre than at its edges, and is used to correct short-sightedness (myopia).

## What is the power of lens A and B?

Thus, the power of the combination of lenses A and B is -5D.

## When object moves closer to a concave lens the image by it shift?

Answer: when an object moves closer to a concave lens the image formed by it shifts away from the lens , it forms real image as we move closer to lens.

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

Detailed Solution

The focal length of the concave lens is always negative. Hence, the given focal length is -2m. Formula: Power = 1/focal length. Hence, Power is -0.5 dioptre.

## What is the focal length of a lens of power 2.0 D?

Focal length of the lens is -50cm or 0.5m.

## What is the power of lens having a focal length of a 50 cm B 50 cm?

Power of a lens is always reciprocal to the focal length. So, aconvex lens with 50cm focal length has a power of (1/0.5) Dioptre(D) or 2D.

## What is the focal length of a lens whose power is 2.5 D?

The focal length will be,-40 cm.

## What is the power of a concave lens of focal length 4 m?

So, the power of the lens is 0.25 D.

## What is the focal length of a lens of power D what type of lens is this?

So, the focal length of the lens is 5 cm. The focal length of a convex lens is positive. So, it is a convex lens.