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GCSE level optics questions

Q17. (a) Ozzy investigates how a lens forms an image of a light bulb.

The image is formed on a screen. Here is the apparatus he used.

(i) Name the process that occurs at the lens to make an image form on the screen.

Refraction

[1 mark]

(ii) Delete the incorrect image properties from the following sentence:

Light arriving on the screen forms an image which is real/virtual and upright/inverted.

[2 marks]

(iii) The student places an object 2.0 cm tall near to the lens. The image formed on the screen is 3.0 cm tall. Calculate the magnification of the image.

magnification = size of image/size of object

magnification = 3.0 / 2.0

magnification = 1.5

[3 marks]

(b) The diagram on the graph paper shows a ray diagram of a converging (convex) lens with an object. The diagram shows two rays of light leaving the object and reaching the lens.

(i) Complete the diagram to show how these two rays form an image.

To get the marks here you need to use a ruler and construct the ray paths carefully.

You need to continue the straight line through the centre of the lens in a straight line path

You have to make the ray travelling parallel to the principal axis pass through the focal point to right of lens

[2 marks]

(ii) Mark the position of the image with an arrow.

(See diagram) the arrow should start on the principal axis and its tip should be where the rays cross.

[1 mark]

(iii) State the name of the two points labelled F on the diagram.

Principal focus or focal point.

[1 mark]


(Total 10 marks)