your MC answers? (1 Viewer)

[cintaurus]

I know I have mistakes in this but they're just what I put down as my answers
But I got:
1. D
2. B
3. D
4. D
5. B
6. A
7. B
8. D
9. A
10. C
11. B
12. B
13. A
14. D
15. A
16. A
17. C
18. C
19. A
20. C

 

[iStudent]

1D
2B
3D
4D
5B
6A
7B
8D
9A
10C
11B
12B
13C
14B
15A
16A
17B
18B (I got this wrong should be D)
19A
20D

 

[hi im trash]

12/20. sooooooo... wonder what the cut off mark for band 5 will be.....

 

[cintaurus]

Shouldnt 18 be C since cathode ray is -ve charge hence the opposite or Left Hand palm rule?

 

[iStudent]

18 is D because force using LHPR is down
also the electric force needs to be up. So the electric field is down (reversed). I got it wrong be a use I misread magnetic field as electric field for the 2nd part of the q :L

 

[mirachael]

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

 

[sisabella]

wheres the paper? someone post it

 

[rated]

D
B
D
D
B
A
B
D
A
C
C (I got B but I changed it to C fk)
D
C
B
A
A
D
D
A
D

 

[orcevalm]

16/20 im pretty sure

 

[Kobweb]

Anyone have a link of the paper?

 

[IR]

dbddbabdaabccbaabdad

 

[IR]

1D
2B
3D
4D
5B
6A
7B
8D
9A
10C
11B
12B
13C
14B
15A
16A
17B
18B (I got this wrong should be D)
19A
20D

Should 12 be c? Since only the torque is effected by radial magnets? Not force? since the coil is always gonna be 90 degrees to magnetic field?

 

[iStudent]

Should 12 be c? Since only the torque is effected by radial magnets? Not force? since the coil is always gonna be 90 degrees to magnetic field?

It can't be C. By your logic the answer would be A (where radial magnets doesn't do anything). Also radial magnets eliminates the theta in f=bilsintheta (since it's always 90). Should be B because it shows it's constant. The second part of the question is sinusoidal like any other typical motor. (in your textbooks), with F=bilsintheta and theta changing causing the force to change as well.

This is a motor effect question right? You have current and your B field. So F=Bilsintheta is the formula you use?

edit: I don't know anymore. Can someone else explain why c?

 

[shadowdragon555]

1. D
2. B
3. D
4. D
5. D (should have been B :/)
6. A
7. A
8. D
9. A
10. C
11. B
12. B
13. C
14. B
15. A
16. A
17. C
18. D
19. A
20. B (Pretty much a guess for this one XD)

 

[shadowdragon555]

Should 12 be c? Since only the torque is effected by radial magnets? Not force? since the coil is always gonna be 90 degrees to magnetic field?

Torque is the turning effect of a force

 

[danielblarg]

It can't be C. By your logic the answer would be A (where radial magnets doesn't do anything). Also radial magnets eliminates the theta in f=bilsintheta (since it's always 90). Should be B because it shows it's constant. The second part of the question is sinusoidal like any other typical motor. (in your textbooks), with F=bilsintheta and theta changing causing the force to change as well.

This is a motor effect question right? You have current and your B field. So F=Bilsintheta is the formula you use?

edit: I don't know anymore. Can someone else explain why c?

This is how I see it. In both diagrams, the wire PQ is always perpendicular to the magnetic field. The radial magnetic field only affects the torque, since with a parallel field not all of the force will be in the direction of rotation.
The magnitude of the force will be unaffected, always being F=BIlsintheta, where theta is always 90 degrees.

 

[iStudent]

This is how I see it. In both diagrams, the wire PQ is always perpendicular to the magnetic field. The radial magnetic field only affects the torque, since with a parallel field not all of the force will be in the direction of rotation. But the magnitude of the force will be unaffected.

Ah I see. Didn't realise PQ was always perpendicular. Yup it's C

 

[IR]

Ah I see. Didn't realise PQ was always perpendicular. Yup it's C

So how much do i get overall for mc? If i can get 20, i would be so happy bc I got 20 in chem.

 

[danielblarg]

I have different answers for 7 and 20 that I'm not sure about.
In 7, the coil should oppose the motion of the magnet by repelling it, which means it has a south pole at bottom and north pole at top, so the magnetic field goes from the top to the bottom, and the current goes clockwise, which is D.
In 20, after 2 seconds the horizontal velocity will still be u, and its at an angle of 45 degrees, so cos45 = u/v, v=u/cos45 = 1.41u, closest to B.

edit: I get 20 now, y velocity is u after 2 seconds so it is D
I can see 7 is B now.

 

[iStudent]

So how much do i get overall for mc? If i can get 20, i would be so happy bc I got 20 in chem.

You got 10 as A?
I think it's C. Otherwise all correct