Tsfx Physics notes scanned and uploaded + questions I have!! help!

[rk]

My name is Rk.
I know barely nothing all about physics.  :uglystupid2:
Borrowed a mate's physics booklet from TSFX to learn something before the actual exam
scribbled on it in pen [fuck!]
may as well make the most of it

I don't understand basically anything.
I've uploaded every second slide [please don't report me to TSFX I can't afford to go to court]
and have annotated what I don't understand

care to help me out?
thanks!!!  :smitten:


edit: There is a LOT i have to ask - 14 queries about certain places in the booklet so I'll upload my scans in sets of a few, I'll wait for the answers then put um more

once again thanks!

[Xavier1234]

That's all there is!
there isn't any. more.

thats a lot of qtns btw. easiest first, do grip rule and you come up with b towards you. thats the b direction, then employ rhs/flem's rule with that direction and you come up with f down.

[Xavier1234]

That's all there is!
there isn't any. more.

firstly, with transmission, Ppri=Psec. knowing that, VpriIpri=VsecIsec. increasing current means you get more e- 'sloshing' around the coil hence more resistance, hence greater power loss. Ploss is denoted by P=I^2 x R. Increasing current increases losses exponentially and you dont want that since it ^ costs.

secondly, knowing the above, If you decrease current, whilst MAINTAINING power value, (P=VI), then P can only be constant IF V is 'stepped up' or 'increased' since you've decreased current to avoid great loss of P. hope that makes sense.

p.s. i wouldnt be surprised if tsfx comes to this thread and asks for the removal of this. i doubt any1 here would report you, but yeah tsfx has long arms. i went to the lecture myself and greg wilmoth is the best lecturer there is. you shoulda gone. =p)

[Xavier1234]

meh I'll put them all up and hope for the best

there will be emf on rq since its inside the field but no emf on ps, so NO it wont have emf flowing through pqrs like a circuit.
the one below it has a net 0 emf since the pq has emf flowing the other direction and sr the opposite.
the third diagram same explanation as the 1st except different sides.

[Xavier1234]

here

1st diagram, no you cant choose, rhs is rhs. force is perpendicular to b accordg to rhs.

[Xavier1234]

here

they almost always give you the length of the coil. unless you are asked to find the length of the coil given that f=this, b=that, i=that. "fangs"?? lol?

[Xavier1234]

here

those are not machines. they are "brushes". they keep electrical contact with the commutator and the the load.

rephrase your question on the force . all i can see from my notes here is the fact that theyre merely telling you that given the angle of the coil at its current position, f=nBILsin(theta), f is decreased. thats it. no calculations or anything

[Xavier1234]

meh I'll put them all up and hope for the best

the flat line means RS do not contribute to the rotation force(torque). why? notice how current in rs is going to LEFT? and the b is going perfectly PARALLEL to the right? knowing that, F=nBIL(sin x 0 theta), then F=0newtons, hence no torque, hence flat line on graph.

[Xavier1234]

meh I'll put them all up and hope for the best

despite lenz's law telling us that the 'bottom' part of the metal tube is gonna be induced a north pole by the falling magnet and REPEL the magnet (hence Mag.force is ^ ), F=nBIL < F=Gmm/r^2.