The principal axis of a convex lens is along x axis. The coordinates of a point object and its image are (-20cm,2cm) and (25cm,-4cm) respectively. What will be its focal length??
Answers
Answered by
0
Focal length: The distance between the center of a lens and its focus is called the focal length.
Given:
X axis coordinate of the object (-20cm, 2cm)
X axis coordinate of the image (25cm, -4cm)
Solution:
According to lens formula,
1 / f = 1 / v - 1 / u
The distance of object distance u = -20 cm
The distance of image distance v = 25 cm
The focal length,
f = ( u v ) / ( u - v )
f = ( - 20 x 25 ) / ( -20 - ( -25 ) )
f ≅ 10cm
Hence, the focal length is 10cm.
Read more on Brainly.in - https://brainly.in/question/6430826
Similar questions