physics 2020 QP
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A-level
PHYSICS
Paper 3
Section B Medical physics
Friday 5 June 2020 Afternoon Time allowed: The total time for
both sections of this paper is
Materials
For this paper you must have: 2 hours. You are advised to
• a pencil and a ruler spend approximately
• a scientific calculator
• a Data and Formulae Booklet. 50 minutes on this section.
Instructions For Examiner’s Use
• Use black ink or black ball-point pen.
Question Mark
• Fill in the boxes at the top of this page.
• Answer all questions. 1
• You must answer the questions in the spaces provided. Do not write 2
outside the box around each page or on blank pages. 3
• If you need extra space for your answer(s), use the lined pages at the end of
4
this book. Write the question number against your answer(s).
• Do all rough work in this book. Cross through any work you do not want TOTAL
to be marked.
• Show all your working.
Information
• The marks for questions are shown in brackets.
• The maximum mark for this paper is 35.
• You are expected to use a scientific calculator where appropriate.
• A Data and Formulae Booklet is provided as a loose insert.
*JUN2074083bB01*
IB/M/Jun20/E6 7408/3BB
, 2
Do not write
outside the
Section B box
Answer all questions in this section.
0 1 . 1 State and explain two differences between the perceived image of a brightly coloured
object in bright light and the perceived image of the same object when viewed in very
dark conditions.
In your answer you should refer to the visual receptors in the eye.
[5 marks]
Difference 1
Difference 2
*02*
IB/M/Jun20/7408/3BB
, 3
Do not write
outside the
According to some legends, in the 17th century a pirate with two healthy eyes covered box
one eye with a patch to keep the eye in the dark. The patch was removed when going
from bright conditions outside to the very dark conditions below decks in an enemy
ship.
It was necessary for the pirate to put the patch on about 45 minutes before going into
the very dark conditions inside the ship.
0 1 . 2 What is the name of the process which occurs when the pirate’s eye is covered by the
patch?
Tick () one box.
[1 mark]
aberration
accommodation
adaptation
adjustment
0 1 . 3 Discuss why it was necessary to wear the eye patch for 45 minutes before entering
the ship.
[3 marks]
9
Turn over ►
*03*
IB/M/Jun20/7408/3BB