Question

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

Answer 1

An object is placed at a distance of 10cm from a convex mirror of focal length 15cm.

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

From above data we have; image distance (u) is -10 cm and focal length (f) is 15 cm.

Using Mirror Formula:

1/f = 1/v + 1/u

Substitute the known values,

→ 1/15 = 1/v - 1/10

→ 1/v = 1/15 + 1/10

→ 1/v = 1/5(1/3 + 1/2)

→ 1/v = 1/5(5/6)

→ 1/v = 1/6

→ v = 6

Therefore, the image distance from the mirror is 6 cm.

Using Magnification formula:

m = -v/u

Substitute the values,

→ m = -6/(-10)

→ m = 0.6

Nature of the image: Erect, diminished and image will formed beyond the mirror.

Answer 2

Given:

• Distance = 10cm
• Focal length = 15cm

To find:

• Position
• Nature of image

Solution:

Using the formula

1/f = 1/v - 1/u

1/15 = 1/v - 1/10

1/15 + 1/10 = 1/v

1/6 = 1/v

By cross multiplying

v = 6cm

Hence , the image formed behind and it is virtual and erect & distance = 6cm