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2 marksLenses

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

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.

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.

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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)(ii)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.[3 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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