Multiple Choice (2 Viewers)

[silence--]

however, when the magnet leaves the magnetic field, there will be another change in mag flux, therefore an induced emf, but it will be in opposite direction (because magnetic field lines are being removed).

nt: i dont even have the paper with me atm so idk even if that is the question you are talking about or whether my answer agrees with A. haha

 

[hscishard]

with 14 would there be eddy currents generated? cause i assumed the split meant no induced current so did D :S

Was confused too. Then I thought about the experiment in a book where a metal had strips taken off. The current was only minimised. Panicked and put C.

 

[damo_g]

Doesn't it contract in the direction of motion? (meaning answer is B)

Dammit i lost a mark on this one. I remember thinking exactly what you said that it contracts in the direction it moves. And i thought of the train in Einstein's thought experiment and how it contracts, and then i picked C. Oh well, looking at the other answers here i still did well.

 

[hscishard]

however, when the magnet leaves the magnetic field, there will be another change in mag flux, therefore an induced emf, but it will be in opposite direction (because magnetic field lines are being removed).

nt: i dont even have the paper with me atm so idk even if that is the question you are talking about or whether my answer agrees with A. haha

Why did I not think that that's -1 so far

 

[CalumGemmell]

Shouldn't 20 be C? The gravitational potential energy is half its initial value, ie it's moving closer to earth. Twice as close, therefore 4 times the gravitational force, right?

 

[silence--]

1.c
2.b
3.b
4.c
5.b
6.c
7.c
8.a
9.b
10.d
11.d
12.a
13.a
14.a
15.c
16.b
17.b
18.b
19.d
20.d

ok i looked my paper, i agree with all this.

now to get off this forum and go and enjoy my life!

 

[cheschirecat]

1.c
2.b
3.b
4.c
5.b
6.c
7.c
8.a
9.b
10.d
11.d
12.a
13.a
14.a
15.c
16.b
17.b
18.b
19.d
20.d

had exactly that.

 

[kleenextissues1]

Shouldn't 20 be C? The gravitational potential energy is half its initial value, ie it's moving closer to earth. Twice as close, therefore 4 times the gravitational force, right?

If grav Ep is halved, then radius is doubled... So according to F = Gm1m2/d^2 , Grav force is quartered... Hence answer is D .... i said this earlier

 

[CalumGemmell]

If grav Ep is halved, then radius is doubled... So according to F = Gm1m2/d^2 , Grav force is quartered... Hence answer is D .... i said this earlier

Oh, fuck. 19/20 now.

 

[Urgh]

Its a repulsive force between the two rods because tey have a cureent in different directions. Hence the distance of the ro depends on the current that glows through them?

dude, the repulsive force is dependent on current and distance, its a dependent variable... the independent variable is what you change to affect the experiment, hence distance between

 

[slavdaddy]

dude, the repulsive force is dependent on current and distance, its a dependent variable... the independent variable is what you change to affect the experiment, hence distance between

What? As u said the Repulsive force is dependant on the current? Sooo te current is the independant? If im mistaken, the distance between them will change unless the top rod is fixed.

 

[kleenextissues1]

What? As u said the Repulsive force is dependant on the current? Sooo te current is the independant? If im mistaken, the distance between them will change unless the top rod is fixed.

The independent variable is what you personally change to obtain diffenrent results. The question says "Rod A was placed at different distances from Rod B"

 

[sicklad]

great, didn't read the questions...10/20 for me it is..

 

[hscishard]

What? As u said the Repulsive force is dependant on the current? Sooo te current is the independant? If im mistaken, the distance between them will change unless the top rod is fixed.

It says "power supply" We dunno if it can vary, but most people will assume it's constant. So I don't think it would be B.

It's therefore A because it's correct.
Trollface.jpg

 

[Urgh]

What? As u said the Repulsive force is dependant on the current? Sooo te current is the independant? If im mistaken, the distance between them will change unless the top rod is fixed.

the current is independent, but its not a variable mate... the distance is the only thing that is varied according to what the question gives, the rod was placed at different distances < variable not reliant on the other factors, check and mate sherlock holmes

 

[slavdaddy]

My mistake, i didnt read the plural in distances. Ahwell 19

 

[Gauss]

What about 14? I had A, but some people have been claiming that the answer was D, as it was not a complete loop. I disagree, an emf will still be induced.

If that is right, i got 20/20

 

[Wight]

What about 14? I had A, but some people have been claiming that the answer was D, as it was not a complete loop. I disagree, an emf will still be induced.

If that is right, i got 20/20

I got A as well. Once the pendulum is in the magnetic field there is no change in flux, so the induced (whatever it was) must be zero?

 

[Fizzy_Cyst]

im a little confused about the question with the pendulum and that split-ring thing.

Does EMF get induced into ring that isn't closed? I thought it did, but I've heard that it doesn't, hence the answer was the constant zero emf graph?

EMF does get induced, but there is no induced current

 

[Gauss]

EMF does get induced, but there is no induced current

That is what i thought. Looks like 20/20 then!