Edexcel iGCSE Physics Paper 1 My unofficial Mark Scheme

srsly tho wtf was up with those polar bears?!?!

that paper was somewhat challenging... Much harder than biology and chemistry in my opinion especially with some of the weirder questions.

Anyway, these are all of the questions/answers i believe i wrote and can remember off the top of my head (i'm pretty sure they're right but feel free to correct me ). There are questions and answers i've missed due to lack of memory.

Questions with calculations, i cannot remember any figures exactly but i can still provide formulas. They are probably in the wrong order but oh well.

1a) constantly velocity = horizontal line on v/t graph
b) distance = area under the line
c) speed = distance divided by time taken

2a) control rod = controls the rate of fission
fuel rod = provides uranium
shielding = protects it (can't remember the exact phrase)

b) moderator = slows the neutrons so they can successfully collide with the uranium and sustain the reaction

c) free neutrons in the reactor start the chain reaction, the moderator slows the neutrons so they can collide with the uranium, this causes the uranium to split up and produce a small number of neutrons which is then sustained by the moderator

3a) week 6 position of comet completes the orbit
b) x (the sun) is marked slightly to the right of week 6 of comet
c) the distance represented between each of the weeks is representative of the speed of the comet, it was faster between week 4-5 than weeks 1-3
d) speed increases as it approaches the sun and there is stronger gravitational pull from the sun
e) orbital speed calculation

4) density and pressure calculations
i used p1 x v1 = p2 x v2

5a) voltmeter drawn parallel to the ldr (one with arrows pointing towards it)
b)

6a) motor effect question - split-ring commutator swaps the brushes/contact every half turn to keep motor rotating in the same direction. Brushes/contacts supply the motor with dc current.
B) reversal of current and magnetic field means it was clockwise, the same as stated in the question (tbf i used fleming's lhs law)

7a) total internal reflection question - refractive index is higher than air ✓, if i = 0 it doesn't deviate ✓, and some other statements
b) graph
c) 2 internal reflections of the jewel should mean the ray of light 'bounces' twice and comes back to the normal
d) refractive index is not given as a unit because it is a ratio between sin i and sin r.it cannot be quantified.

8) hooke's law experiment - describe how the apparatus can be used to prove hooke's law

measure the original length of the spring without any masses attached. Ensure the ruler is vertical and measure it at eye level. Add 1 mass at a time and let the spring come to rest before measuring the new length. The extension is the difference between the new length and the original length. Do this for at least 6 measurements. Repeat the experiment and calculate an average length of spring for each applied weight.

Plot your data on a graph of force vs extension, you should see the extension is proportional to the force applied as there is a straight-line relationship

9a) circumference and calliper calculations
b) why results differ between averaging a cirumference and using digital calliper to calculate diameter

10) calculations for work done and power
work done = force x distance
power = work done / time

11a) train question
calculating velocity using the ke formula so

v= √(ke divided by (1/2 x mass)

b) gpe is gained from the lift because it is increasing in height and ke is lost and converted to gpe

c) slopes... More work done is needed to overcome the gravitational pull (can't remember what i wrote for this)

12) polar bears (oh god)
a) heat energy is the same as in the polar bear's body and snow because it is absorbed
b) hairs in the fur trap air which acts as a wall of insulation which limits the amount of heat loss via convection
c) white colours reflect whilst black absorbs
d) uv light is absorbed by the sky
e) the uv waves don't reach the skin because they partially get absorbed by the tube and it partially passes through. Also, total internal reflection cannot occur so it can't reach the skin.

I subtracted it from the water pressure

what do you think the grade boundaries will be? also, what did you add the atmospheric pressure and the pressure difference together in the diver question? loads of my friends are complaining but i swear im right

I still hope they're around 75% like last years but who knows.

As for that, you should have subtracted the pressure difference from the atmospheric pressure because it said what was the increase, can't remember the exact figure tho

I still hope they're around 75% like last years but who knows.

As for that, you should have subtracted the pressure difference from the atmospheric pressure because it said what was the increase, can't remember the exact figure tho

Surely not, cus the formula finds the difference in pressure anyway, regardless of atmospheric pressure

i don't exactly have the best of memories but I remember the atmospheric pressure was 101 kPa and you had to subtract that from a large kPa figure as it asked for the increase (i.e. the difference between the two numbers)

i don't exactly have the best of memories but I remember the atmospheric pressure was 101 kPa and you had to subtract that from a large kPa figure as it asked for the increase (i.e. the difference between the two numbers)

I still hope they're around 75% like last years but who knows.

As for that, you should have subtracted the pressure difference from the atmospheric pressure because it said what was the increase, can't remember the exact figure tho

what was the total marks for the polar bear question??

I totally failed that exam. Goodbye A*...

I was feeling pretty confident after how easy Biology and Chemistry were, but I have faith that the grade boundaries will be low because only about 2 people I know thought it actually went well. It's just annoying that I've done so badly on the one I'm planning to take for A-level!