GCSE OCR Physics P4,5,6 UNOFFICIAL MARKSCHEME

could u say u make the wires thicker and shorter for resistance

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You got the P5 6 marker wrong - the lens makes this image smaller as it is between 1 and 2 focal points, inverted and a real image, the length is 1.5cm (I think)

There was a question in p6 about primary and secondary coils and you have to write down a output voltage of the secondary with was 2000A or 200A i think (cant remember)

there was a question where you had to talk about the construction of the step down transformer

there was a question where you had to work out the speed of the boat and its direction which ws 5m/s and 53.1 or 53 degrees

I believe that is incorrect in the sense that you have calculated the direction as 53 degrees. Let me ask you this, of you are travelling faster in the north direction than the east, would you be more inclined to travel less than 45 degrees or more than 45 degrees? I believe the answer to be 36.87 degrees from the horizon.

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did u use tan?

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Just realised you can do 38.57 from the north line and 50-something from the horizon. Apologies

in section D there was a few more questions about the stupid pendulum
im pretty sure i got the second to last one right about the time taken for the pendulum
the equation was like T = 2pi x root(length/gravity) or smth
anyway i got 3.4
Thanks for thissss

what...?

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You can do the direction from the north line and the horizon so depending on how you answered the question it could be either

I believe that is incorrect in the sense that you have calculated the direction as 53 degrees. Let me ask you this, of you are travelling faster in the north direction than the east, would you be more inclined to travel less than 45 degrees or more than 45 degrees? I believe the answer to be 36.87 degrees from the horizon.

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wooo gcses over ok here's the sad truth, please tell me if i got something wrong or forgot something- still working on this

P4
Question on Plugs:
-Live- carries voltage of about 230V/ mains
-Earth- used for safety and for a safe path for current to go to
-Neutral- completes the circuit, carries no charge

Calculate Resistance
-6/3=2 Ohms

How can she reduce overall resistance without voltage:
-decrease resistance on variable resistor
-increase current due to R=V/I

Fill in numbers for fusion:
-2
-3
-something

cold fusion: why is it important that scientists share data
-peer review
-reproduce the experiment and collab

why is gamma a good industrial tracer:
-doesn't get stopped by ground or most walls so is good for detecting leakage

half life-
how does carbon12 and carbon14 change after death
-carbon12 stays same
-carbon14 decays at 5730 years for half of its nucleus

-22920 years

6 marker- Nuclear Fission
-label: neutron fired, nucleus (uranium), nucleus splits, releasing more neutrons, chain reaction
-Diff between that and bomb: bomb is uncontrolled fission, station is controlled by (boron)rods which absorb neutrons
P5
What would happen to satellite if tangential force is too high or low
-if too high then it would escape earths orbit
-if too low then grav att will pull it towards earth

What's the advantage of a low flying artificial satellite:
-can travel very fast around globe taking HQ images of weather

which wave for transmission: (mixed opinions)
C- the one that went through atmosphere as the satellite can get the signal unaffected or unscattered

diff between vector and scalar:
-vector has direction

resultant velocity: 5m/s in north east direction, it asked for direction and speed not sure if you had to use trig

basketball q about horizontal velo:
-horizontal distance is unaffected as there is not gravity acting upon it so horizontal velocity is constant
-vertical distance is reduced at peak of throw as grav acts upon it

suvat-
v=u+at
u=v-at
11-6=5m/s (forgot the answer soz)

how does the particle theory not prove interference:
-if particles collided they would bounce off each other and not interfere like waves do i.e. contructive and destructive

6 Marker- Lens diagram
-7/7.5cm, real, inverted, formed after lens image
How convex lens work: direct line from top of object through optical centre, line from top of object parallel to principal axis to top of lens which refracts and passes through focal point, converges light

P6

diode
- only allows positive voltage so from +end to -end not other way round

explain how it works:
-just explain diagram lol

transformer:
voltage- 5000V
how it forms: (idek)
-soft iron core in mould
-wires coiled around each end

why isolating transformers;
-equal primary and secondary voltage so shaver works
-safety, prevents shocks or electrocution

capacitors:graph like a (_ shape
-explain how a capacitor gains voltage or something
probe question:
-risk: could explode, hard to maintain
-benefitrobe can be off all the time until capacitor wake it up

6 Marker Logic Gates: 1,0,0,0,1,1,1,1
-the logic gate needs a relay because:
1. the voltage and current of the mains circuit would severely damage the logic gate
2.the current emitted from logic gate is too low to power the main operated motor so needs a relay
SECTION D

Pendulum

-3.4
-0.25

for the resultant velocity question in p5 you had to use trig, i'm 99% sure you did because i came out of the exam and looked it straight up in the revision guide and asked all my friends lol. I think the direction was like 56 degrees