Q1.When glass is placed in a liquid of the same refractive index, the glass seems to disappear. This method can be used to determine the refractive index of small pieces of glass.
(a) The refractive index of some types of glass and some liquids is given in the table.
Type of glass / Refractiveindex / Liquid / Refractive
index
Bakeware glass / 1.47 / Methanol / 1.33
Car headlight glass / 1.48 / Water / 1.33
Window glass / 1.50 / Alcohol / 1.37
Bottle glass / 1.52 / Olive oil / 1.47
Spectacle glass / 1.54 / Castor oil / 1.48
Lead glass / 1.62 / Cinnamon oil / 1.60
(i)Use information from the table to give an example of a type of glass and a liquid where the glass would seem to disappear.
Type of glass ......
Liquid ......
(1)
(ii)What is the range of refractive index of the liquids in the table?
From ...... to ......
(1)
(iii)Which type of glass has a refractive index outside the range for the liquids?
......
(1)
(b) The diagram shows a ray of light travelling from air into glass.
(i)What is the name given to the dashed line?
......
(1)
(ii)Draw, on the diagram, the letter i to label the angle of incidence.
(1)
(iii)Draw, on the diagram, the letter r to label the angle of refraction.
(1)
(i)The value of i is 46° and the value of r is 29°.
Calculate the refractive index of the glass.
Use the correct equation from Section B of the Physics Equations Sheet.
......
......
Refractive index = ......
(3)
(ii)Look at the table in part (a).
Name a type of glass that could have been used in part (b).
......
(1)
(Total 10 marks)
M1.(a) (i)headlight glass and castor oil
or
bakeware glass and olive oil
1
(ii)1.60–1.33
either order
1
(iii)lead (glass)
do not accept 1.62
1
(b) (i)normal
1
(ii)i correctly labelled
allow I for i
accept with or without arc
1
(iii)r correctly labelled
allow R for r
accept with or without arc
1
(c) (i)1.48(375…)
1.5 scores 3 marks
allow:
n = 0.719 / 0.484 for 2 marks
n = sin 46 / sin 29° for 1 mark
3
(ii)car headlight glass
ecf from (c)(i)
1
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