Page 684 - SUBSEC October 2017_Neat

-4- 02138032/SPEC/K/MS/JUNE 2017

PHYSICS
UNIT 1 — PAPER 032
MARK SCHEME

Question 3

KC UK XS
(a) Identification of variables

Identifies light intensity of source (1), distance from
source to sample (1) and distance from sample to detector 3
(1) as variables. [3 marks]

(b) Setup of apparatus

Accurate labels (1) 3
Correct placement of essential apparatus (2)
Award 1 mark only if one piece of apparatus incorrectly
placed.
[3 marks]

(c) Procedure

 Excludes other light sources (1)
 Keeps distance from source to sample constant (1)

 Keeps intensity from source constant by monitoring
4
with a light meter (1)

 Measures intensity of source with light intensity

meter (1)

[4 marks]

Results
(d)

3
Plot results (1) should show a decrease in light

intensity with thickness (1). No direct proportional

variation between light intensity and thickness (1).

[3 marks]

Conclusion
(e)

Valid conclusion drawn from results (1). Results

following the inverse square law (1).
2
[2 marks]

Total 15 marks 15