Question

An object with size 5cm is placed at 35cm in front of a concave mirror of focal length 25 cm.at what distance from the mirror should the screen should be placed so that a sharp focussed image can be obtained find
the nature and size of the image

Answer 1

Answer:

Image is virtual, erect and magnified

Explanation:

ho = 5 cm

u = -35 cm

f = 25 cm

1 /v + 1 /u = 1 /f

1 /v = 1 /25 - (-1 /35)

      = 1 /25 + 1 /35

1 /v= 60 /875

v = 14.5 cm

hi / ho = - v /u

hi /5 = -14.5 /-35

hi = 2.07 cm

Magnification is positive, image is enlarged.

Image distance is positive, image is virtual and erect.