Want to compare multiple-choice answers? (1 Viewer)

[Lachdog]

that is incorrect. The answer is C

By using basic trig, Sin 45 = 0.4 / L
Therefore 0.4 = L.sin45

By using the formula F = BILsin@

B = 0.5 T
A = 3 A
Lsin@ = 0.4

Therefore F = 0.6 N

That is exactly why the answer is 7d. You said L.sin45 = .4. that means,

L=.4/sin45.
L=.5656.....
F=BIl
F=.5x3x.5656...
F=.849 N. Definately 7 d

 

[hysteria85]

Sweet according to the tabulated results above I got 15/15.

Are the 'correct' answers there just the most common ones? or have they been verified by a teacher or something?

 

[hysteria85]

my bad double post

 

[arkanisw]

that is incorrect. The answer is C

By using basic trig, Sin 45 = 0.4 / L
Therefore 0.4 = L.sin45

By using the formula F = BILsin@

B = 0.5 T
A = 3 A
Lsin@ = 0.4

Therefore F = 0.6 N

owned.. that's what they WANT you to do. but it isnt, read the other posts comments about θ being 90 degrees.

sigh, tricky ppl those examiners. check out the post i set up "Things examiners want you to get wrong" for a list that you may also have got fooled in

 

[carra330]

but isn't it perpendicular to magnetic field?
hence, it starts off with max flux [sin@] and then decreases to 0 as it is parallel .. and yeah.

that's what it thought ~_~

hey

sorry to disappoint any of you who picked 8 a or b, the actual answer is c, as flux is not a vector quanity so it will never be negative, leaving the only answer/graph as c. Dont worry i was in the same arguement with half my class when we walked out, whether it started with max or min, and i thought b, but then our physics teacher stepped in and stood us all down and told us it was c, and that we were all wrong . And yes he is a reliable teacher, considering he got 99/100 for his extension maths test when he did school --FREAK!!!!

 

[helper]

hey

sorry to disappoint any of you who picked 8 a or b, the actual answer is c, as flux is not a vector quanity so it will never be negative, leaving the only answer/graph as c. Dont worry i was in the same arguement with half my class when we walked out, whether it started with max or min, and i thought b, but then our physics teacher stepped in and stood us all down and told us it was c, and that we were all wrong . And yes he is a reliable teacher, considering he got 99/100 for his extension maths test when he did school --FREAK!!!!

Maybe he should have a discussion with professor joseph f becker, san jose university
http://www.physics.sjsu.edu/becker/physics51/induction.htm