• Support PF! Buy your school textbooks, materials and every day products Here!

Magnetic field q

  • Thread starter debwaldy
  • Start date
38
0
1. Homework Statement
Two parallel wires 10 cm apart carry antiparallel currents of 1A and 3A respectively.
(i) what is the force per unit length(in magnitude and direction) between the wires
(ii) what is the magnetic field midway between the wires?
(iii) locate the point(s) where the magnetic fields cancel.


2. Homework Equations
F/L = 2*10^-7(I1)(I2)/d
H= I/2piR


3. The Attempt at a Solution

(i) i said F/L = 2*10^-7*(1)(3)/(0.1)= 6.0*10^-6 Nm^-1 and direction is repulsive.is this the correct method?

(ii)here i used the formula H=I/2piR
i used this on each wire and took the average value,although this doesn't seem correct:

H1= 1/2*pi*(0.05)= 3.183 A/m
H2 = 3/2*pi*(0.05) = 9.5492 A/m

and H= H1+H2/2 = 6.366 A/m

(iii) i wasn't too sure what to do here but i said that the magnetic fields would cancel wherever they were equal however this only gave me 0m as my answer....

any help would be great thanks
:biggrin:
 

Answers and Replies

Related Threads for: Magnetic field q

  • Last Post
Replies
5
Views
4K
Replies
2
Views
962
Replies
8
Views
5K
  • Last Post
Replies
1
Views
944
Replies
1
Views
10K
  • Last Post
Replies
3
Views
4K
  • Last Post
Replies
2
Views
414
Top