Question

find the position and nature of an image of an object 5 cm high and 10cm in front of a convex lens of focal length 6cm​

Answer 1

Given that, an object 5 cm high and 10 cm in front of a convex lens of focal length 6 cm.

We have to find the the position and nature of an image.

Form above data we have; height of object (h) is 5 cm, image distance (u) form the lens is -10 cm and focal length (f) is 6 cm.

Using Lens formula:

1/f = 1/v - 1/u

Substitute the known values,

1/6 = 1/v - 1/(-10)

1/6 = 1/v + 1/10

1/v = 1/6 - 1/10

1/v = 1/2(1/3 - 1/5)

1/v = 1/2(2/15)

1/v = 1/15

v = +15

Therefore, the image distance from the lens is +15 cm. (Positive sign means image is formed on the right side of the lens.) Image is formed behind the lens.

Now, using Magnification formula:

m = v/u = h'/h

Substitute the values,

m = 15/(-10)

m = -1.5

Image formed will be real and inverted.