an object 4.0cm in size is placed at 25.0cm in front of a concave mirror of focal length 15.0cm at what distance from the mirror should a screen be placed in order to obtain a sharp image. find the nature and the size of the image ?
Answers
Answered by
24
★ Check this attachment...
Attachments:
Answered by
21
Explanation:
Given,
size of object , H₀ = 4cm
object distance , u = -25cm
focal length of concave mirror , f = -15cm
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 , 37.5cm 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
Hence,sreen should place 37.5 cm left side of mirror and size of image is 6cm .it is inverted and larger than object's size.
Similar questions