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## Can the focal length be negative in a convex lens?

If you are talking about a biconvex lens then it can not have a negative focal length if the surrounding medium is denser than the lens. But for a convex-concave lens, **if R2>R1 and no>nlens**, you can have a negative focal length.

## Is focal length of convex positive?

In convex lens, the focal length is **positive**.

## Is focal length of a convex 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.

## Can the convex lens be negative?

For a convex lens, focal length (f) is positive and for **a concave lens, the value of f is negative**. So by assigning signs to focal length in the power formula (PL=1f) we get negative value for concave lens and positive value for convex lens.

## Why is focal length of concave lens negative?

**The power of the lens is the reciprocal of the focal length**. A concave lens is a diverging lens, so it will always have a negative focal length. Therefore, the power of a concave lens is also negative.

## 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.

## Why is focal length positive for convex lens?

Convex lens **converges incident rays**. Hence the rays to converge at a point in front of the lens. So image distance is positive here. We can easily clarify that the focal length is positive direction for a Convex lens while negative with concave lens.

## What is the formula of focal length of convex lens?

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. 2.

## Is the power of concave lens positive?

Complete answer:

The power of the **concave lens is negative**. Concave lens surfaces have a virtual radius of curvature, and thus a negative curvature. Optical power is denoted by the same convention signs that are used for focal length.

## Which lens has positive power?

(a) **Convex lens** has positive power.

## Can a converging lens have more than one focus?

Lenses have two focuses, each on the two sides of the mirror. Converging lens can have **more than one focus depending on where the object is and focuses have to have same distance from the centre**.

## Are real images always inverted?

Real image is found when the rays of light converge at a point after reflection on a mirror or after refraction through a lens. … If we placed an object above the x-axis then by geometry the rays will converge below the axis. Therefore, the image formed will be an inverted image. Hence, **a real image is always inverted**.

## Is object distance ever negative?

Explanation: **Object distance is always negative as per the sign conventions**. … Such an image is produced when the object is kept at a distance less than the focal length of the lens.