
#1
Feb1212, 12:43 PM

P: 102

1. The problem statement, all variables and given/known data
(i) Find the magnitude and direction of the magnetic field at the point O located at a distance D = 10 cm from a wire carrying a current i = 1.0 A directed into the page, as shown in the attached drawing. (ii) A second wire, identical to the first, is placed a distance D = 10 cm on the opposite side of O from the first wire as shown in Figure 3. This second wire carries a current with the same magnitude of i = 1.0 A. In which direction must this current flow in order for the magnetic field strength at O to be non* zero? 2. Relevant equations Right hand grip rule B(r) = μ i / 2π r 3. The attempt at a solution For (i) I've got the magnitude of the field as 2uT from the B(r) = u i / 2π r and the direction as downwards using the right hand grip rule. For (ii) I'm assuming that for it to be non zero then the current would have to be directed out of the page  if it was into the page then the resultant would be zero? 



#2
Feb1212, 02:46 PM

Emeritus
Sci Advisor
HW Helper
PF Gold
P: 7,391

(i) I didn't check the numbers, but that's the way to calculate the Bfield at point O For (ii), You have the correct result, but it's not so much an assumption as it is a wellreasoned conclusion. 



#3
Feb1212, 03:00 PM

P: 102

Thank you SammyS (i) that's exactly what the question asked for and (ii) I thought so... cheers  I feel so much better now.



Register to reply 
Related Discussions  
Need serious help with right hand rule please for magnetic fields  Introductory Physics Homework  7  
Right hand grip rule in rotational kinematics  Classical Physics  2  
Right Hand Rule for Magnetic Fields  Classical Physics  2  
Righthand rule regarding magnetic fields  Introductory Physics Homework  13  
Right Hand Rule and Magnetic Field  Introductory Physics Homework  5 