What is the energy density at the center of a circular loop of wire carrying a 23.0 A current if the radius of the loop is 25.0 cm?

A coil of radius 3 cm has 60 turns of Cu wire of diameter 4 mm. The plane of the coil is perpendicular to a field that changes at the rate of 0.2 T/s. What is the power loss in the coil? The resistivity of Cu is 1.7 × 10-8 S. m. mW

Five parallel wires carry currents into or out of the page, as shown in the diagram below. The line integral of B around the loop (in the direction indicated) is +µoI where | = 1.0 A. I,=4.0A Iz=8.0A L=1.0A I=7.0A ? Is What is the unknown current I5? OA. 8.0 A out of the page. 8.0 A into the page. 5.0 A into the page. 5.0 A out of the page.

Suppose in the figure that the four identical currents i = 20 A, into or out of the page as shown, form a square of side 76 cm. a) What is the force per unit length (magnitude and direction) on the wire in the bottom left hand corner? (N/m) Take the positive y direction as up and the positive x direction as to the right. b)What is the magnitude of the force per unit length?  c)What is the x component of the force per unit length?  d)What is the y component of the force per unit length?