Question

The focal length of a concave mirror is 15cm. Find the position of the image of an object placed at a distance of 25cm from the mirror​

Answer 1

Answer:

Explanation:

size of object , H₀ = 4 cm

object distance , u = -25 cm

focal length of concave mirror , f = -15 cm

Use formula ,

1/v + 1/u = 1/f

⇒1/v + 1/-25 = 1/-15

⇒1/v = 1/-15 + 1/25 = (-25 + 15)/375 = 1/-37.5 cm

⇒ v = - 37.5 cm ,

∴ image is formed object side , 37.5 cm from pole of concave mirror.

Now, use formula,

Hi/H₀ = -u/v

Where Hi is the size of image .

Now, Hi/4cm = -(-37.5cm)/(-25cm)

Hi = -4 × 37.5/25 cm = -6cm

# size of image = 6cm  

the image is formed behind the mirror. Since the Distance is Negative, thus the Image is Real.

hope it will help u dear!