Physics: Discussion, Questions & Potential Solutions

[wanigara]

what was the momentum mcq answer??

(Q8) C which is 4.0 ms-1 and (Q9) B Kinetic energy is not conserved but momentum is conserved.

[Richard Feynman 101]

Spot on with Q9 (this has been tested before and done so badddd)

[Freddie Hg]

(Q8) C which is 4.0 ms-1 and (Q9) B Kinetic energy is not conserved but momentum is conserved.

na the hisenbergs one

[aussiboi]

When solutions coming we finish in 2.5 hours and they take whole day DONT TAKE THIS SRSLY

[wanigara]

Short Ans (Q2)
(a) emf = 6.4x10^-4 V
(b) Emf - time graph: Loop Outside Field = 0 V Loop Entering Field= -V, Loop Inside Field = 0V Loop Leaving Field =+ V Loop Outside field = 0 V.

[aussiboi]

Short Ans (Q2)
(a) emf = 6.4x10^-5 V
(b) Emf - time graph: Loop Outside Field = 0 V Loop Entering Field= -V, Loop Inside Field = 0V Loop Leaving Field =+ V Loop Outside field = 0 V.

It was 3 marks so how are marks gonna be distrubuted

[wanigara]

na the hisenbergs one

(Q15 D. Uncertainty in their y- position affects the uncertainty in their y - momentum

[Bri MT]

When solutions coming we finish in 2.5 hours and they take whole day DONT TAKE THIS SRSLY

I get that VCE is stressful and you want reassurance but the solutions are put together for free? It's a nice thing that people do to help out;  not a service which you're entitled to. The people who do this also have their own responsibiliies


I'm pretty sure people have already posted MC answers, but if answers aren't up by tomorrow I'll write them


Edit: sorry, didn't see your "don't take this seriously" (despite the all-caps)  but yeah, will do the solutions tomorrow if not sorted before then

[wanigara]

It was 3 marks so how are marks gonna be distrubuted

Most likely for calculating change in flux - 1 mark
Subbing no  emf = - n*Change in flux / change in time - 1 marks
Final answer - 1 mark

[aussiboi]

Most likely for calculating change in flux - 1 mark
Subbing no  emf = - n*Change in flux / change in time - 1 marks
Final answer - 1 mark

Sorry i meant for that emf graph we had to draw cos i got it all wrong i drew a sin graph rippp

[Richard Feynman 101]

I get that VCE is stressful and you want reassurance but the solutions are put together for free? It's a nice thing that people do to help out;  not a service which you're entitled to. The people who do this also have their own responsibiliies


I'm pretty sure people have already posted MC answers, but if answers aren't up by tomorrow I'll write them

Chill bra. "Don't take is srsly". FFS.

[wanigara]

Q3 (a) Clockwise. Current flow in the coil H to G, magnetic field is to the right (N to S), using RH Force rule force on side HG Down and Force on Side EF is Up. Hence the rotational force (or torque) is clockwise, thus coil would rotate clockwise.

(b) Motor will not spin continuously in one direction with slip-rings. Because it dose not reverse the direction of the current in every half rotation as it does with spilt-ring commutator.

With slip rings coil will begin to spin. However after its passes the vertical orientation, it will spin in the anti-clock direction. After a few oscillations, coil will come to rest when plan of the coil is vertical.

[Freddie Hg]

Q3 (a) Clockwise. Current flow in the coil H to G, magnetic field is to the right (N to S), using RH Force rule force on side HG Down and Force on Side EF is Up. Hence the rotational force (or torque) is clockwise, thus coil would rotate clockwise.

(b) Motor will not spin continuously in one direction with slip-rings. Because it dose not reverse the direction of the current in every half rotation as it does with spilt-ring commutator.

With slip rings coil will begin to spin. However after its passes the vertical orientation, it will spin in the anti-clock direction. After a few oscillations, coil will come to rest when plan of the coil is vertical.

keep em comin

[wanigara]

Here are the answers (q) 4 , 5  & 6

4(a) Vrms is the DC equivalent voltage = 4/ SQRT(2) = 2.83 V
4 (b) Doubling in frequency will double the emf and half the period. You should draw double amplitude (+/- 8 V).

(5) (a) Current in the Globe 4 x 3 = 12A, Voltage = 4.0 V, So Power dissipated in the globe = 12x4 = 48W
(b) V output = Vdrop in the line + V Primary coil = 3x8 + 16 = 40 V
(c) P loss = I^2 R = 72 W

(d) Assume Globe still operate at 48 W and the V = 4.0 V.
Current in the Globe = 12A. Therefore the current in transmission line = 12 / 8 = 1.5 A, Ploss = I^2 R = 18 W

(e) - For constant power increasing voltage would reduce current in the transmission line (P = VI). High current contributes to increasing  Fire Risk, thus low current reduces fire risk.

- Also High voltage in the line or lower current in the line contributes to lower lower loss as Ploss = I^2R. So more efficient power transmission can be achieved by High voltage electric power transmission. 

[wanigara]

Sorry i meant for that emf graph we had to draw cos i got it all wrong i drew a sin graph rippp

Most probably: 1 - Mark for overall shape of the graph, 1- Mark correct magnitude  1- Mark one constant V is negative and the other V is positive.