URGENT HELP FOR A2 PHYSICS ><

[Anneihtseme]

URGENT HELP, MY EXAM IS COMING IN LESS THAN 7HRS
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w07_qp_4.pdf
any one helps me with the question 5b (ii)
The questions to use the given diagram to determine the initial charge.
Here is what the mark scheme says:

(ii) area is 21.2 cm2 (allow ±0.5 cm2) .......................................................................C2
(allow 1 mark if outside ±0.5 cm2 but within ±1.0 cm2)
1.0 cm2 represents (0.125 × 10-3 × 1.25 =) 156 μC ..............................................C1
charge = 3300 μC .................................................................................................A1(ii) area is 21.2 cm2 (allow ±0.5 cm2) .......................................................................C2
(allow 1 mark if outside ±0.5 cm2 but within ±1.0 cm2)
1.0 cm2 represents (0.125 × 10-3 × 1.25 =) 156 μC ..............................................C1
charge = 3300 μC .................................................................................................A1​

Examiner's report

Successful candidates either counted squares or used a series of vertical strips. The conversion of
the area to a charge presented few problems apart from a power-of-ten error. A significant number
of candidates found the area of a single strip near to the origin on the x-axis. Presumably they
thought that this initial strip would represent the initial charge stored in the capacitor.​