A2 Physics questions, urgent help needed

[KaiserFury]

Hello,

I have a few questions that I'm hoping you guys can answer asap, as my exam is after tomorrow.

I want to know what to write down as my answer when the question is "What is seen on the screen when electrons are diffracted", first as particles and second as waves. As in, concentric circles and stuff. And why, if possible.

I would also like to know, in AM and FM, how to calculate the carrier frequency and the signal frequency, and how to solve part 10(c) in this paper: http://www.xtremepapers.com/CIE/ind... Level/9702 - Physics/&file=9702_s07_qp_4.pdf

http://www.xtremepapers.com/CIE/ind... Level/9702 - Physics/&file=9702_s08_qp_4.pdf
In number 2, part b(iii) of this paper, the mark scheme says the mass melted by heater in 5 minutes is = 64.7 - 0.5 x 16.6. Why is this? Why isn't it just 64.7 - 16.6?

In a reaction, when one nucleus gives off another nucleus and energy, how can the second one be the one having more binding energy if the first one was able to turn to the 2nd one and give off excess energy?

What's the difference between thermionic emission and the photoelectric effect?

I would greatly appreciate any help with my enquiries.

Thank you.

 

[smzimran]

There is already a thread for this!
Post it there

 

[KaiserFury]

I posted there and no one answered me.