Table 3 Values for the x-component of the magnetic field for various values of r and x. (i) At r = 0, over what approximate range of x does B remain above 98% of its value at the origin of the coordinate system? Consider negative coordinates as well the positive x coordinates shown in the table. (ii) At x = 0, over what approximate range of r does B remain above 98% of its value at the origin of the coordinate system? (iii) What is the approximate shape of the volume in which B is above 98% of its value at the centre? Give the approximate dimensions of this shape. Hint: You may find it useful to consider how the field will evolve with rotation about the x axis.

A rod with radius R = 2.02 mm is carrying a current of 13.0 A. determine the magnetic field at the following distances from the center of the rod. a) r(a) = R/2   b) r(b) = 3R/2

A piece of wire carrying a current of 2.5 A is bent into a quarter circle arc of radius 15 cm as shown below.  Determine the direction of the magnetic field at point P.  The answer for the direction is one of the symbols in the second picture, options a through d.

As shown in the figure below, two long parallel wires (1 and 2) carry currents of I, = 3.24 A and I, = 4.85 A in the direction indicated. %3D P (a) Determine the magnitude and direction of the magnetic field at a point midway between the wires (d = 10.0 cm). magnitude µT direction 90 ° counterclockwise from the +x-axis (b) Determine the magnitude and direction of the magnetic field at point P, located d = 10.0 cm above wire 1. magnitude direction ° counterclockwise from the +x-axis

The magnetic field 38.0 cm away from a long, straight wire carrying current 3.00 A is 1580 nT. (a) At what distance is it 158 nT? cm (b) At one instant, the two conductors in a long household extension cord carry equal 3.00-A currents in opposite directions. The two wires are 3.00 mm apart. Find the magnetic field 38.0 cm away from the middle of the straight cord, in the plane of the two wires. nT (c) At what distance is it one-tenth as large? cm (d) The center wire in a coaxial cable carries current 3.00 A in one direction, and the sheath around it carries current 3.00 A in the opposite direction. What magnetic field does the cable create at points outside the cables? nT

Two long wires are oriented so that they are perpendicular to each other. At their closest, they are 20.0 cmcm apart (Figure 1).   What is the magnitude of the magnetic field at a point midway between them if the top one carries a current of 22.0 AA and the bottom one carries 13.5 AA ? Express your answer using three significant figures.   B=?

magnetic fields Problem 19:   Consider the two wires in the figure, running at a right angle to each other. The wires carry the same current I = 6.5 mA, in the directions shown. The distances shown are d1 = 31 cm and d2 = 11.5 cm.   Part (a)  What is the magnitude of the magnetic field, in tesla, at point A?  Part (b)  What is the magnitude of the magnetic field, in tesla, at point B?  Part (c)  What is the magnitude of the magnetic field, in tesla, at point C?