Page 8 - Science E-Book Prep.3 2024-2025 1st term_ unit 2_Neat

Science Department
Prep.3

How to determine the focus and the focal length of the concave mirror
Steps:
1.Place the concave mirror facing the
sun rays(faraway object) ,move the
Screen facing the reflecting surface
of the mirror to get a lit point at
which weget the smallest and
clearest image which is the focus of
the mirror.
2- Measure the distance between the lit point(F) & the pole of the mirror(P).

Conclusion:
The measured distance is the focallength of the concave mirror
Focal length = ½ Radius of curvature f = ½ R or R = 2 f

First Term 26