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GCSE level optics questions

Q9. A student investigated how the nature of the image depends on the position of the object in front of a large converging lens. The diagram shows one position for the object.

(a) Use a ruler to complete a ray diagram to show how the image of the object is formed.

 

Award marks as follows:

  • Ray through pole of lens is undiverted.
  • Ray parallel to the principal axis passes through the principal focus after refraction by the lens.
  • Image point should be joined by a perpendicular line to the principal axis with an arrow head on the top of it.

Rays should have an arrow on them - no arrow means it is not a ray. Therefore lack of arrow heads on rays - deduct 1 mark.

No ruler used - deduct 1 mark

(4 marks)

(b) Describe the nature of this image relative to the object.

It is inverted, magnified and real (3 max)

(2 marks)

(Total 6 marks)