1. Determine and record the approximate focal length f\(_{o}\) of the concave mirror provided.
2. Arrange the ray box, the mirror, and the screen as shown in the diagram above.
3. Adjust the ray box to a distance b = 20.0cm from the mirror.
4. Adjust the position of the screen until a sharp image of the cross wire of the ray box is formed on it.
5. Measure and record the distance, a, of the screen from the mirror. Evaluate \(\frac{a}{a}\) =1.
6. Repeat the procedure for four other values of b = 25.0, 30.0, 35.0, and 40.0cm. Tabulate your readings.
7. Plot a graph of l on the vertical axis against a on the horizontal axis.
8. Determine the slope,.s, of the graph. Evaluate S\(^{-1}\).
9. State two precautions taken to ensure accurate results.

(b)i. An object is placed at a distance of 10cm in front of a concave mirror of focal length of 15cm. Determine the characteristics of the image formed.

ii. Briefly describe how you obtained f\(_{o}\) in (a)i) above.