Question

An object is placed at a distance 15 cm from a convex lens of focal length 10cm. Find the image distance and nature of the image.​

Answer 1

Answer:

Image Distance = 30cm

Nature is Beyond Center of Curvature

Explanation:

In case of Convex Lens,

Object distance, u = -15cm

Focal Length, f = 10cm

Now, using the lens formula,

1/f = 1/v - 1/u

1/v = 1/f + 1/u

1/v = 1/10 - 1/15

1/v = 1/30

Therefore v = 30cm

Answer 2

Answer:

The image distance is +30 cm. The image formed is real, inverted, and enlarged.

Explanation:

The object distance, u = -15 cm

Focal length of the convex lens, f = +10 cm

We have the lens formula as,

1/f = 1/v - 1/u

⇒ v = (uf) / (u + f)

   v = (-15 × 10) / (-15 + 10)

∴ v = +30 cm

So th image distance, v = +30 cm

Magnification of the image, m = v/u

                                                  = +30 / -15

                                              m = -2

The negative sign of magnification indicates that the image is real and inverted. The value of magnification greater than one indicates that the image is enlarged.