You have been provided with a ray box, a converging lens, a lens holder, a screen, a metre rule, and half- metre rule. Use the diagram above as a guide to perform the experiment.

(i) Determine the approximate focal length f, of the lens by focusing a distant object on the screen.

(ii) Place the ray box and the screen such that the distance between the illuminated cross-Wire and the screen, D= 150 cm.

(iii) Place the lens at a position L where a sharp mage of the cross-Wire Is obtained on the screen Note L.

(iv) Move the lens at a position L, to 0btain another sharp image of the cross-wire on the screen. Note L

(V) Measure the distance, d. between L\(_1\) and L\(_2\).

(Vi) Evaluate D\(^2\): d\(^2\) and D\(^2\) - d\(^2\).

(vii) Repeat the procedure for four other values of D = 130cm, 100 cm, 90 cm and 80 cm. in each case.evaluate D\(^2\); d\(^2\) and D\(^2\) - d\(^2\).

(viii) Tabulate the result

(ix) Plot a graph with D\(^2\) - d\(^2\) on the vertical axis and  D on the horizontal axis.

(x) Determine the r values of D axis and  Determine the slopes, S, of the graph.

(xi) Evaluate k = \(\frac{s}{4}\)

(xii) State two precautions taken to ensure accurate results.

(bi) Distinguish between a virtual image and. plain image?

(ii) With the aid of a ray diagram, explain how a converging lens produces a Virtual image