May 2021
Just did paper 1 HL. Didn't know that tunneling probability was related to mass, and am not sure if field lines are a visual representation or a theory to explain concepts. ( I'd go for visual representation) The force time graph question was a bit overdone, the muons will throw students a bit as will the V-t graph. The last question is easy but disguised as something difficult. Apart from that seems fine. All the usual sort of graph and ratio questions. A fair paper with some twists to test the students understanding.Here are my answers. Sorry about the mess but I picked out a paper that had beeen worked on by one of my students. They did quite well I think.
I realised that I can't post the IB paper here, sorry.
HL Paper 2 looks OK. (1) I like the fact that the projectile question is solved using components and not memorised equations for range and max height that some students rely on. (2) The gas question is straight forward. (3)SL students will find the electrostatics question difficult since they will have to use the vertical comp to find the horizontal one. Why did the thread break? Classic potential not zero when field is zero question. (4)On first look at the decay equation I didn't realise the large boxes were there to be filled in, thought it was some sort of collimator. Students will find the question about half life difficult. (6)Students might not realise that photocells have internal resistance, however they will when they do part b (2 free marks). (7) Wow, 4 marks for explaining why the pendulum slows down. I always tell my students it's not just about doing calculations, explanations often carry more marks. (8)Hopefully students will see the bold second order. A nice twist. One of my students calculated the mean by calculating the slits per mm for each point, I guess they were supposed to use the gradient. (9)The photo electric question is straight forward and doesn't include the usual same intensity - different wavelength conundrum. (10)A spacecraft is sent from Io to infinity! good luck with that one. Again a fair paper with some nice but not too devious twists.