i found it hard too
yeahh i found the question in multiple choice was quite hard and tricky
however this is my answer
Q1 (a) since based on the equation sqrt of ux^2 + vy^2
Q2 (d) the orbital decay is always caused by the atmosphere and this causes a drad that leads to the decrease of the speed
Q3 (B) since 1/2mv^2=GMm/r and the small m is getting eliminated the mass of space probe not affect the magnitude of escape velocity
Q4 (c) i doubt it some people in my school think that it is either c or d, but my argumentation is that the deceleration is the one that is used in the hohfmann's transfer to move to the planet that is on the inner orbit of the earth, since the Rocket P in the picture decelerated the rocket must have changed its orbit to become an elliptic orbit that is tangent to both the origin orbit and the new orbit, but it don't know
Q5 must be C!... why 90-50degress is just the same as 40
Q6 (d) i guess, because the lease likely to affect the copper wire, however i think we are all get it wrong north to south to south and east to weast means that the angle is 0degrees, not 90, and why it is maximum? because the equation of induced emf is blvcostheta, not F=bilsintheta
Q7 it must be D!
Q8 don't wannt to tell you it is something that makes me feel confused :<, i know the battery is DC but it also gets a switch?? the question is ambiqious
Q9(B) since the induced eddy current happens in both tube Q and R, however the tube R is not a full circle and because of that the area is not maximum that reduces the induced eddy current therefore the magnet that is droppd to the tube R appears to be having faster than Q
Q10 (D) i know most people think that it is B but if you use the right hand rule you will know that both B and C still having a high induced eddy current that will cause heat, why d? because in the picture D it gets large number of strips
Q11 B
Q12 A
Q13 A or C ? hehehehe it made me confused because as we know the band theory of solids, the gap between the conduction band and the valence band we call it by forbidden gap, how about if you think like this, if we add more number of electron the condution band should be doped with more layer to fill the conduction band ??? it is obviously confused us, but since we know that the number of electron is available in both bands isn't it?
Q14 (B)
Q15 (B) some students in my class think it is also D but some of them deriving an expression qvb=qe(the force between the magnetic field when it is applied to the electrons) they eliminate q then become v=e/b, which means the speed of electron (the charge e) is slows down due to magnetic field of magnitude (b) but i don't that's right!!!
i guess don't put too much worry on this, everyone knows it is hard so i hope our mark will get scaled up