OCR GCSE Physics Paper 4 (Higher tier) J249/04 - 23 Jun 2022 [Exam Chat]

Do you think the grade boundaries will be lower this year, cos personally, I think the advanced information didnt actually help, unlike maths for instance, as all the topics were tested like previous years, and they put P1 questions where its meant to be P5-P8, it was very easy though but still. And they said about generous grading, so who knows

for the second part of the last question, I said that lower radius means stronger gravitational attraction between the planet and the sun, so the planet has to travel/orbit faster around the Sun to keep up with the orbit. I expanded on that though, but is that enough for 2 marks. And for the 3 marker, I talked about scalar and vector and gravitational forces acting on the planet. For some reason, I talked about centripetal forces which seemed irrelevant and I dont know if i said something wrong, so dunno if I got full marks on that

for the circuits question, did you have to add a variable resistor

i only really said what you said for the 2 marker and didn't expand on it. for the 3 marker i did the same and talked about centripal forces and the fact that it was at right angles to the acceleration

I only said centripetal forces and talked about gravitational force so is that enough do u think

Do you think the grade boundaries will be lower this year, cos personally, I think the advanced information didnt actually help, unlike maths for instance, as all the topics were tested like previous years, and they put P1 questions where its meant to be P5-P8, it was very easy though but still. And they said about generous grading, so who knows

here's a list of things i remember from the paper if anyone wants to be reminded/discuss them

- Work done investigation (block of wood with masses on)
- Plotting and interpreting graph
- Why lubrication required less work done
- Sound reflection (echo) and why it’s quieter in echo
- Calculating distance and why using stopwatch is inaccurate
- How sound travels to ear, in ear, and how frequency changes wavelength
- Isotopes, how beta radiation effects them
- Gamma used in tracers and why, including why half-life is 6 hours
- 6 marker on safety of cars
- Finding voltage and current (in circuit) and specific heat capacity questions (find specific heat capacity of 2kg block, 25 degrees difference, 20kJ). Suggest why it’s higher (energy loss) and suggest improvement
- 3 specific heat capacity graphs and which one has highest SHC
- Wind turbines questions (why output is 0 at low wind and high wind, why generation has increased, efficiency 5 mark question)
- Electricity calculations (off graph and resistance calculation) + transformer question (p.d. on secondary coil and why higher p.d. results in less power loss)
- Why speed isn’t changing but speed is referring to forces in orbits
- Why smaller radius requires higher speed
- Proving why one thing isn’t proportional to the other

Multiple choice: rate of cooling, light refraction through trapezium block, red light on blue, nuclear fission after 3 steps, p and s-waves (which will reach other side of earth), microwave question (energy transfers), specific latent heat, amplitude of wave, thinking distance under graph, mW in W, half-life of thing, radiation intensity graph, if extension doubles how will 5J change

You



For the wind turbines questions(not 5 marker), I said that energy is 0 at less than 3.5 because wind turbines are moving really slowly so there isnt enough electricity thats being supplied so therefore, people cant cook food, watch TV and play videogames, for e.g. For greater than 25, I said something like if the wind turbines go beyond that speed, it can break, meaning that electricity isnt generated so people cant cook food, and that wind turbine can only work up to a certain speed. Is that a good answer do you think?
Apparently, I said lubrication reduces friction, which increases the speed , but then waffled (maybe on the same sentence) that it causes greater acceleration and greater force, dunno if that still deserves one mark as the first part is definitely right

For the wind turbines questions(not 5 marker), I said that energy is 0 at less than 3.5 because wind turbines are moving really slowly so there isnt enough electricity thats being supplied so therefore, people cant cook food, watch TV and play videogames, for e.g. For greater than 25, I said something like if the wind turbines go beyond that speed, it can break, meaning that electricity isnt generated so people cant cook food, and that wind turbine can only work up to a certain speed. Is that a good answer do you think?
Apparently, I said lubrication reduces friction, which increases the speed , but then waffled (maybe on the same sentence) that it causes greater acceleration and greater force, dunno if that still deserves one mark as the first part is definitely right

And for the sound question in terms of why the distance isnt accurate, I said that some energy is lost/dissipated when sound waves travel to the cliff and reflected back and also, I said less repeats, as only one result is taken? How much marks do you think that would be

i found out the scale factor of the radius and multipled one of the speeds by the scale factor and it didn't equal the other speed so it couldn't be proportional

in the question it stated that it was timed using a stopwatch so i just talked about human error (may start too late and may mishear echo etc.)

my prediction for this paper would be 71-72/90, is that a grade 9 do you think(It's very unrealistic for the grade boundaries to rapidly spiral since examiners were told to be more generous)