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Since X-rays have extremely short wavelength, Braggs though that by subjecting a crystal structure to X-ray beams information about lattice structure could be gathered. They used an X-ray tube to emit uniform X-ray beams through collimators towards the lattice structure so they remained parallel...

I got c aswell.

It is certainly a regurgitating dot point, but I would also add the WW2 short comings in technology. Mobile communciation devices were required for pilots to contact base towers, but thermionic devices were bulky and required significant power to operate and thus more funds were directed towards...

we used an ice cube mould. One layer was the valence band the other was the conduction band. Marbles were used to represent electrons. It was noted that when an electron migrated from the valence band to the conduction band, it left behind an employ space, that is , a positive hole. Also, when...

staying up until I finish the content. don't think will get any past papers done. Usual plan. sleep at 2. Wake up at 6. start studies. Go to school at 8.45 FKKKKKKKKKK CANT WAIT TO FINISH THIS SHIT

hope 2012 exam is like this - 90% of my cohort will stuff up though. (except hole flow lol - don't understand that)

anyone good in medical physics MRI section? really struggling.

If you look at some marking criteria. they don't even have "3 marks for correct answer" Some 3+ calculation questions they look at your working and give you the marks if all your calculations and everything is correct.

get it today? Also, if you are mildly sick it would probably be better to the physics exam. I think they give people an estimate or something with misadventure form.

Do we have to know the other? I only know the one you discussed. Explain why superconductors are advantageous to be used in computers.

hmm. I know that DC can be stepped up or down but it is difficult and inefficient to do so. I would think something like this: - Ovbiously, there needs to be a changing magnetic flux - so if you have a turn on coil on one side and 2 turns on another side of an iron pole, you could turn on the...

Ahh thanks for clearing that up :) Any good/nice questions ?

Say AC electric motor (not induction), since the current constantly changes, hence changing flux, it would lead to induction of emf in the wires right? :/ Which would mean its less efficient than DC for a given power which will have no emf induced. Not 100% sure though, but was thinking about...

LOL I was going to say, it lights up your room. btw for a given power supply, which motor is more powerful, AC or DC and why?

what lol? magnetic flux density being less? Haven't heard of that you can see it via the right hand palm rule. They attract when in the same direction. Depends on the question, if its a 2 marker. saying same direction--> attract is enough.

solid state: - small size--> thermionic devices involve vacuum tubes and are bulky--> limits their use on more complex electrical systems. - efficient--> thermionic devices have significant heat dissipation thus electrical energy is lost as heat where as solid state devices lose only a fraction...

for a given power supply, which motor is more powerful, AC or DC and why?

Bolded part should be enough. Say an object is at a certain position in the earth's gravitational field and has a certain value of GPE. Now, for its GPE to change, there has to be a change in its position in the gravitational field right? For this change in position to occur work must be done...

But its 5 marks. 1 mark of each property and explaining should get 5 i think :/ Also, note, she said, there isn't much space for writing.

you just regurgitate the wave and particle properties of cathode ray? e.g. moves a paddle wheel--> momentum-->hence mass--> hence particle (according to early studies) 2 of each would be enough for 5 marks.