Another doozie for me. I have been trying this one for 3 days now. I will give my first born for help to this one :uhh: --------------- Calculate the magnitude and direction of the magnetic field produced at point P in Fig. 28.52 by the current I in the rectangular loop. (Point P is at the center of the rectangle.) (Hint: The gap on the left-hand side where the wires enter and leave the rectangle is so small that this side of the rectangle can be taken to be a continuous wire with length b.) Diagram ----------- I am using law of Biot and Savart(dB=(mu*I*dl x r)/(4pi*r^2)) I took the lines into four parts and started calculating what the magnetic field parts would be and then summ'ed them as by right hand rule the field will be into the page. B1 is the left side, B2 is the top, B3 is the right and B4 is the bottom. B3=B1=Mu*I*b/(Pi*a*sqrt(a^2+b^2)) B4=B2=Mu*I*a/(pi*b*sqrt(a^2+b^2)) Btotal=B4+B3+B2+B1=2Mu*I*b/(Pi*a*sqrt(a^2+b^2))+2Mu*I*a/(pi*b*sqrt(a^2+b^2)) Can anyone please help me?