Page 760 - SUBSEC October 2017_Neat

-4- 02238032/SPEC/K/MS/JUNE 2017

PHYSICS
UNIT 2 — PAPER 032
MARK SCHEME

Question 2
KC UK XS
(a) (i) By extrapolation, 8Ω (1) 1
[1 mark]

(ii) Reading off values from graph (1 XS)
Gradient, read off values and calculate, for example: 1
(64-0)/(10-1.2) = 7.2 V(1 UK) 1

[2 marks]

(iii) 1/I = 4 A
R = 20Ω (1 XS)
P = I R or P = IV or P = V R (after finding V using 1
2
2
equation given) (1 UK) 2
2
P = (0.25) x 20 = 1.25 W (1 UK)
[3 marks]

(b) (i) Both would double: E = 14.4 V; r = 16 V (2)
[2 marks] 2

(ii) I (A) 1/I (A ) R (Ω)
-1
0.1 10 77

0.2 5 37
0.5 2 13
0.8 1.25 7
1.0 1 5

1/I column correctly calculated (1)
R column correctly calculated (2) 3
[3 marks]

(iii) Plotting of graph

4 accurate points (2)
2-3 accurate points (1)
<2 accurate points (0)
Suitable scales(1)
Accurate labeling(1) 4
[4 marks]

Total 15 marks 5 10