1. 1
   A collector holds a convex (converging) magnifying glass close above an old coin to examine the fine detail of its engraving. Looking through the lens, the coin appears larger than it really is.

   (a)

   What type of image is formed when a convex lens is used as a magnifying glass in this way?

   [1 mark]

   • AVirtual, upright, and magnified
   • BReal, inverted, and magnified
   • CReal, upright, and the same size as the object
   • DVirtual, inverted, and diminished

   (b)

   If parallel rays of light (such as rays from a very distant object) were to pass through this same convex lens, what would happen to them?

   [1 mark]

   • AThey would spread further apart as if coming from a single point
   • BThey would be brought together (converge) at the principal focus of the lens
   • CThey would continue travelling parallel to each other with no change
   • DThey would be completely absorbed by the lens

   (c)

   State what is meant by the focal length of the convex lens, and explain, in terms of the position of the coin relative to the lens, why the collector must hold the coin close to the lens (within its focal length) to see a magnified image.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   An optometrist is testing the eyesight of a patient who has been struggling to read text held close to her face, although she can see distant objects clearly. The optometrist explains that this is a sign of long sight.

   (a)

   Which structure inside the eye normally changes shape, controlled by the ciliary muscle, to focus light from objects at different distances onto the retina?

   [1 mark]

   • AThe cornea
   • BThe pupil
   • CThe lens
   • DThe retina

   (b)

   Which type of lens would the optometrist prescribe in a pair of glasses to correct the patient's long sight?

   [1 mark]

   • AA concave (diverging) lens
   • BA lens made only from coloured glass
   • CA flat piece of plain glass with no curvature
   • DA convex (converging) lens

   (c)

   Explain, in terms of where the image forms in relation to the retina, why a long-sighted person struggles to focus clearly on close objects.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A photographer compares how a camera and the human eye each bring a scene into focus. In the camera, the distance between the lens and the light-sensitive sensor is mechanically adjusted for different subject distances. In the eye, the distance between the lens and the retina stays fixed.

   (a)

   Compare how the eye and a camera each achieve a focused image, describing the key difference between the two focusing methods.

   [3 marks]

   (b)

   The photographer takes a picture of a 5 cm tall object, and measures the height of its image on the camera sensor as 1 cm. Calculate the magnification of the image, and state what this value tells us about the size of the image compared with the object.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A patient with short sight (myopia), who can focus clearly on close objects but sees distant objects as blurred, visits a laser eye surgery clinic. The surgeon explains two possible options: wearing glasses with concave lenses, or undergoing a laser procedure that reshapes the surface of the cornea.

   (a)

   Explain why a short-sighted eye forms a blurred image of distant objects, and explain how a concave lens in a pair of glasses corrects this problem.

   [6 marks]

   (b)

   Discuss the laser surgery option offered by the clinic as an alternative to wearing glasses, including what lasers can be used for in this context, and suggest one advantage and one disadvantage of choosing laser surgery over wearing concave lens glasses.

   [6 marks]

   Total for question 4: 12 marks

End of questions