Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: wire tension



Phys-L is great; a minute after posting the message, and
before receiving any reply, I had a hint. Cut the circle in
two parts, upper and lower. Tension is the net vertical
force on each half. I will try the integration now.
Ludwik Kowalski

Ludwik Kowalski wrote:

A circular loop of flexible wire is placed in a uniform
magnetic field perpendicular to its plane. The radius of
the loop is R and its current is I. What is the tension?
The end of the book answer is: T=I*B*R.

How can this be derived? I know that each dL element
is subjected to the radial outward force B*I*dL. But
tension is a tangential force. Intuitively I do expect tension
to be proportional to the radial force per unit length (I*B)
but I do not know how to demonstrate that T=I*B*R.
Ludwik Kowalski