7. Consider a long straight wire with diameter of 2 mm carrying a current of 1 amp. Assume that the current density is uniform. What is the magnetic field at the center of the wire? What is the magnetic field at a radius r = 0.5 mm from the center? At r = 1.0 mm from the center? Take the permeability H= Ho everywhere. 2 I=| Amp R= Imm

A 11-cm-long straight wire is parallel with thex axis and carries a current of 1.8 A in the +x direction. The force on this wire due to the presence of a magnetic B is 2.8 N -2.2 N k. Determine the magnetic field B. B = (C field + 2.2 N k. If this wire is rotated so that it is parallel with the y axis with the current in the +y direction, the force on the wire becomes -2.8 N

Two parallel wires are separated by 0.25 m. Wire A carries 4.1 A and Wire B carries 10 A, both currents in the same direction. The magnetic permeability in empty space uo = 47 × 10-7 T-m/A. The magnitude of the force on 1.4 m of Wire A is: Select one: O a. 2.6 x 10 N. O b. 4.6 x 10 N. O c. less than 1.0 x 10 N. O d. 3.2 x 10s N.

Niobium metal becomes a superconductor when cooled below 9 K. Its superconductivity is destroyed when the surface magnetic field exceeds 0.100 T. In the absence of any external magnetic field, determine the maximum current a 4.64-mm-diameter niobium wire can carry and remain superconducting. A Additional Materials O eBook

0.01 T magnetic field points south and downward, 45o below the horizontal. A proton travels south at 500 m/s. What is the force on the proton? In the figure below, east points out of the page and west points into the page.

9. Two long, straight wires are separated by distance, d = 21.0 cm. The wires carry currents of I₁ 2.50 A and I2 = 8.50 A in the same directions, as shown in the figure. Find the magnitude of the net magnetic cm, r2 = field at point (B). Let r₁ = 13.0 7.00 cm, and r3 = 14.0 cm. T r₂ OSS SS 09- A B ssf60 ssf60 ssf60 s60 ssf60 ssf60 ssf60 ssf60 f60 ssf60 ssf60 ssf60 ssf60 ssf60 ssfo d £60 *$$ (9js8 09888 f60 s: 60 ssf60 ssf60 ssf60 ssf60 ssf60 ssf60 f60 ssf f60 ss$60 ssf60 ssf60 ssf60 ssf60 ssf60 ss

A given neuron in the brain carries a current of 3.1 * 10-8 A. Ifthe SQUID detects a magnetic field of 2.8 * 10-14 T, how far awayis the neuron? Treat the neuron as a straight wire.A. 22 cm B. 70 cmC. 140 cm D. 176 cm

A 3.0 uC charge moves horizontally due east with a speed of 4.0*10^5 m/s. A magnetic field of 1.2 T is due north at an angle of 30 degrees below horizonal direction. 1. What is the magnitude of the force on the charge?  a. 1.00 N b. 1.44 N c. 0.72 N  d. 1.25 N 2. What is the direction of the force on the charge? a. Into the earth  b. Out of the earth c. North 60 degrees above horizontal d. South 30 degrees below horizontal

A current I = 30 A is directed along the positive x-axis and perpendicular to a magnetic field. A magnetic force per unit length of 0.18 N/m acts on the conductor in the negative y-direction. Calculate the magnitude and direction of the magnetic field in the region through which the current passes. magnitude      ________T direction     a. +x direction b. -x direction c. +y direction d. -y direction e. +z direction f. -z direction

22