TEST OF PRACTICAL KNOWLEDGE QUESTION Fix a metre rule on the bench with the graduated face up. Place the illuminated object at the zero end of the rule and ...

TEST OF PRACTICAL KNOWLEDGE QUESTION

1. Fix a metre rule on the bench with the graduated face up.
2. Place the illuminated object at the zero end of the rule and the screen at the other end as illustrated in the diagram above.
3. Measure and record D, the distance between the object and the screen. Evaluate D\(^{2}\).
4. Place and move the converging lens between the illuminated object and the screen until a diminished sharp image of the object is formed on the screen. Read and record the position, X\(_{1}\), of the lens. From this position, move the lens towards the object until another sharp image of the object is formed on the screen. Read and record the new position x\(_{2}\), of the lens.
5. Evaluate and record L (x\(_{1}\) - x\(_{2}\)), L\(^{2}\)) and (D\(^{2}\) - L\(^{2}\))
6. Repeat the procedure for D = 90, 80, 70 and 60 cm. In each case, evaluate, L L\(^{2}\) and (D\(^{2}\) - L\(^{2}\)). Tabulate your readings.
7. Plot a graph of D\(^{2}\) - L\(^{2}\) on the vertical axis against D on the horizontal axis.
8. Determine the slope, S, of the graph and evaluate K = \(\frac{s}{4}\). State two precautions taken to ensure accurate results.

(b)i. Distinguish between a real image and a virtual image.

Draw a ray diagram to show how a converging lens may be used to form a real diminished image of an object.