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3 marksImage Formation

CSEC Physics · January 2018 · Paper 2 · Question 5(b)(ii)

A homemade projector is constructed from a cardboard box, a cellphone, a cellphone stand, and a magnifying glass embedded into one face of the box, as shown in Figure 5. The focal length of the lens is 15.0 cm.

If the phone is placed 20 cm from the lens, calculate the distance the screen must be placed from the lens in order to obtain a clear image of the phone.

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Other parts of this question

  1. 5(a)State what evidence each proposed and whether this evidence supported the wave theory or particle theory.[4 marks]
  2. 5(b)(i)Suggest, with a reason, an appropriate distance from the lens at which the phone should be placed in order to get a magnified image on an external screen.[2 marks]
  3. 5(b)(iii)Calculate the magnification of the image on the external screen formed in (b)(ii).[3 marks]
  4. 5(b)(iv)If the dimensions of the phone screen are 11.0 cm × 6.0 cm, calculate the dimensions of the image of the phone screen on the external screen.[1 mark]
  5. 5(b)(v)State whether the image formed in (b)(ii) is upright or inverted.[1 mark]
  6. 5(b)(vi)Suggest one way in which the image formed in (b)(ii) can be made larger.[1 mark]

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