The segment of wire in the Figure, carries a current of I = 3.00 A, where the radius of the circular arc is R = 2.50 cm. Determine the magnitude and direction of the magnetic field at the origin

I can't seem to figure out this what I missing from my calculation can you help me with this?

A current i = 2.0 A flows in a long straight wire and in a circular loop as indicated in the figure below. If the distance a = 3.0 cm, what is the magnitude of the magnetic field at point P at the center of the loop? Express your answer to the nearest µT.

A steady-current flows down a long cylindrical wire of radius R. Find the magnetic field, both inside and outside the wire, if the current is distributed in such a way that J is proportional to r², where r is the distance from the axis.

There are three parallel wires perpendicular to the paper, each carry ing current I that are located at the vertices of a right triangle. The current is coming out of the paper for wires 1 and 2 and into the paper for wire 3. Point A is at the midpoint of the hypotenuse. d 45⁰ 2 A 45° d (X) 3 Calculate the net magnetic field vector (both magnitude and direction) at A.