Question

an object 4cn in size is placed at a distance of 25cm from a concave mirror of focsl length 15cm. find the position,nature and size of image​

Answer 1

Answer:

Answer. ⇒ v = - 37.5 cm , ∴ image is formed object side , 37.5 cm from pole of concave mirror.

Answer 2

Given:

• Object height ,h = 4 cm

• Object Distance ,u = -25 cm

• Focal length ,f = -15 cm

To Find:

• Position , Nature & Size of Image.

Solution:

Firstly we calculate the Image Distance

Using mirror formula

❒• 1/v + 1/u = 1/f

where,

v is the Image Position

u is the object distance

f is the focal length

Substitute the value we get

→ 1/v + 1/(-25) = 1/(-15)

→ 1/v -1/25 = -1/15

→ 1/v = -1/15 + 1/25

→ 1/v = -5 +3/75

→ 1/v = -2/75

→ v = -75/2

→ v = -37.5 cm

Therefore,the image distance is 37.5 cm from the object.

Now, Calculating the Magnification

• m = hi/ho = -v/u

where

hi denotes height of image

ho denotes height of object

v image distance

u object distance

Substitute the value we get

→ hi/4 = -(-37.5)/-25

→ hi/4 = 37.5/-25

→ hi = -37.5×4/25

→ hi = -6 cm

here negative sign show the image is inverted.

Nature of Image :- Image formed is Real and enlarged .