An object 2 cm in size is placed 20 cm in front of a concave mirror of focal length 10 cm. Find the distance from u the mirror at which a screen should be placed in order to obtain sharp image. What will be the size and nature of the image formed?
Given,
Height of object h1= 2cm
Object distance u= -20 cm
Focal length of concave mirror f= -10 cm
To find:
Distance of screen = Image distance v=???
Height of image h2=???
We know that mirror formula is:
Substituting the given values in the formula:
v = -20 cm
Screen should be placed at distance 20 cm from mirror in order to obtain sharp image
In other words, screen should be placed at distance 20+20 = 40 cm from the object in order to obtain sharp image.
Image will be formed in front of the mirror, i.e. real.
Also,
Height of image = - (Height of object)
This means that image is of same size as the object but it is inverted.