Semicircles of current Due in 11 hours, 4 minutes A current is set up in a wire

Question

Semicircles of current Due in 11 hours, 4 minutes A current is set up in a wire loop consisting of a semicircle of radius 5.50 cm, a smaller concentric semicircle, and two radial straight lengths, all in the same plane. Part (a) of the figure shows the arrangement but is not drawn to scale. The magnitude of the magnetic field produced at the center of curvature is 57.2 . The smaller semicircle is then flipped over (rotated) until the loop is again entirely in the same plane (part (b) of the figure). The magnetic field produced at the (same) center of curvature now has magnitude 12.4 , and its direction is reversed. What is the radius of the smaller semircircle? 0.0781 cnm Submit Answer Incorrect. Tries 7/10 Previous Tries

Explanation / Answer

figure a

magnetic field to to smaller semicircle B1 = uo*I/4r

magnetic field to to larger semicircle B2 = uo*I/4R

total magnetic field Ba = B1 + B2 = (uo*I/4)*(1/r + 1/R)

given Ba = 57.2*10^-6 T

figure b

magnetic field to to smaller semicircle B1 = uo*I/4r

magnetic field to to larger semicircle B2 = -uo*I/4R

total magnetic field Bb = B1 + B2 = (uo*I/4)*(1/r - 1/R)

given Bb = 12.4*10^-6 T

Ba/Bb = (1/r + 1/R)/(1/r - 1/R)

57.2/12.4 = (1/r + 1/5.5)/(1/r - 1/5.5)

radius of smaller semicircle r = 3.54 cm <<<---------ANSWER

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.