Joining two wires, magnetic fields and a little algebra

AI Thread Summary
To find the magnetic field strength on the line joining two wires with currents flowing, the equation B = μ iD / π(D² − d²) can be derived. This involves summing the contributions of the magnetic fields from both wires at a point a distance d from the midpoint O. A relevant trigonometric identity, (D² − d²) = (D + d)(D - d), is useful in simplifying the calculations. The standard formula for the magnetic field due to a long straight wire, B = μ i / 2π d, serves as a foundational reference. The discussion highlights the need for clarity in applying these concepts to solve the problem effectively.
shyguy79
Messages
99
Reaction score
0

Homework Statement


Consider a general point on the line joining the two wires and a distance d
away from the mid-point O. By summing the magnetic field due to currents of magnitude i flowing in both the wires which are non-zero, show that on the line joining the two wires, the magnetic field strength is given by:

B= μ iD / π(D2 −d2)

Homework Equations


(D^2 −d^2) = (D+d)(D-d) ****** a simple trig identity
B= μ i / 2π d

The Attempt at a Solution


I'm kinda stuck - any pointers on where to start?
 
Physics news on Phys.org
Just bumping it back up - anyone any ideas?
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top