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Question 18M.3.SL.TZ2.a

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Date May 2018 Marks available [Maximum mark: 3] Reference code 18M.3.SL.TZ2.a
Level SL Paper 3 Time zone TZ2
Command term Suggest Question number a Adapted from N/A
a.
[Maximum mark: 3]
18M.3.SL.TZ2.a

An optic fibre of refractive index 1.4475 is surrounded by air. The critical angle for the core – air boundary interface is 44°. Suggest, with a calculation, why the use of cladding with refractive index 1.4444 improves the performance of the optic fibre.

[3]

Markscheme

sin c =  1.4444 1.4475  or sin c = 0.9978

critical angle = 86.2«°»

with cladding only rays travelling nearly parallel to fibre axis are transmitted

OR

pulse broadening/dispersion will be reduced

 

OWTTE

[3 marks]

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