GCSE level optics questions

Q8.The diagram shows an object located vertically on the principal axis of a diverging lens. A student looks through the lens and can see an image of the object.

(a) Using a pencil and ruler to draw construction lines on the diagram, show how light from the object enters the student's eye and the size and position of the image.

See the diagram:

  • One ray from the object point should go undiverted through the pole of the lens into the eye
  • One ray should travel parallel to the principal axis up to the lens line. It should then emerge from the lens as if it has come from the virtual focus - this should be shown with a dashed line.
  • The image arrow should be a dashed arrow pointing to the point where the ray and construction line cross.

(3 marks)

(b) Describe the nature of the image by comparing it to the object.

The image is samller than the object (diminished in size) , it is closer to the lens than the object is (image distance < object distance) ,

It is also virtual whereas the object is real but the two above is what the examiner required.

(2 marks)

(Total 5 marks)