## yrelhan4 2 years ago a wire is bent as a parabolic curve kept in x-y plane. the curve can be described by the equation x^2=6y. if a uniform magnetic field B=2*10^-3 k tesla (positive z direction) is applied, force experienced by the wire is nearly?

1. yrelhan4

oops. the wire carries a current i=2A

2. shubhamsrg

length ?

3. yrelhan4

|dw:1359707566710:dw|

4. shubhamsrg

So the wire extends from (-6,6) to (6,6) only right ?

5. yrelhan4

we dont know the x coordinates.

6. shubhamsrg

Oh am sorry, I don't know why assumed the height to be 6, nevermind.

7. shubhamsrg

Okay, so the working formula is F = iBl

8. shubhamsrg

Where are you stuck ?

9. yrelhan4

what should be l? or i always use idl * b. dl here..

10. shubhamsrg

l = distance between 2 ends of wire.

11. yrelhan4

we should have x coordinates then?

12. shubhamsrg

nopes. distance between the ends is already given right,

13. shubhamsrg

|dw:1359708383481:dw|

14. shubhamsrg

Is that 6 ? or the co-ordinate on y axis (0,6) ?

15. yrelhan4

coordinate on y axis.

16. shubhamsrg

I see, then use the given eqn, find co-ordinates of x, as I said before, they should come out to be (-6,6) and (6,6)

17. yrelhan4

ohho.. ok. damn. it was easy. :P thank you.

18. shubhamsrg

you should also be able to find out direction of force, can you tell me what will that be ?

19. yrelhan4

-j?

20. shubhamsrg

Yep, ^_^

21. yrelhan4

hmm. thank you. :)

22. shubhamsrg

Note that direction of force is different at different points on the force, -j is the direction of net force. Anyways, glad to help.

23. shubhamsrg

different at different points of the wire*