Question

an object of 4.0 cm in size is placed at 25 cm in front of concave mirror of focal length 15cm,find the image distance, nature and the size of the image

Answer 1

since the lens is concave values of f , v , u are in negative
So, -1/15 = -1/25 -1/v
i/v = 1/15 - 1/25 = 5 - 3 / 75
v = 37•5.
size of image = 37•5 × 4/25 = 6cm .
Nature of image virtual erect enlarged