O Level 2016 Sci(Physics) Practical Examination - Converging Lens

1. It is very easy to score the Science (Physics) Practical Examination. All you need is to READ the question and FOLLOW THE STEPS carefully.

2. First read through the entire question paper for initial understanding.

3. (2a.) Determine the average diameter d of the hole forming the cross-wire object.

4. (b) Set up the apparatus shown in Fig. 2.1.

5.  (c) Move the lens along the rule until a sharply - focused magnified image of the object is formed on the screen.

6. (i) Measure the distance between the centre of the lens and the screen.

(ii)  Determine the average diameter D of the image formed on the screen. 

(iii)  Calculate the magnification m of the image, using the relationship m  = D/d.

7 (d) Repeat the different values of x.

8. (e)  Using the grid opposite, plot a graph of m against v.

9. (f)  Determine the gradient and find the numerical value of the focal length.

Note:

Please take note that once the distance x, reaches 70 cm, the image becomes magnified instead of diminished (smaller). 

This is because the the object is nearer to the focal length, as such the image becomes magnified.