i knw the pics not tht clear but its like tht one in resnick halliday........u have to find the magnetic field at pt. P.....here the arrow shows the direction of the current. here theta and thedistance of pt.Pfrm the circular arc keep varying .... while the magnetic field due to both straight wires comes to be zero....... wat do i do ????? pls guys its a piece of cake 4 u all..............reply and get rated.....if a person tell the answer by a differnt method he too will get rated...........

Use moving electrically charged particles, such as a current in a wire, to make an electromagnet. y Magnetic field is a basic characteristic of elementary particles (such as electrons) just as mass and electric charge (or lack of charge) are basic characteristics. y These particles have an intrinsic magnetic field around them. y Permanent magnet: The magnetic fields of the electrons in certain materials add together to give a net magnetic field around the material. y In other materials, the magnetic fields of the electrons cancel out, giving no net magnetic field surrounding the material