A circular coil (960 turns, radius = 0.083 m) is rotating in a uniform magnetic

Question

A circular coil (960 turns, radius = 0.083 m) is rotating in a uniform magnetic field. At t = 0 s, the normal to the coil is perpendicular to the magnetic field. At t = 0.028 s, the normal makes an angle of 45o with the field because the coil has made one-eighth of a revolution. An average emf of magnitude 0.071 V is induced in the coil. Find the magnitude of the magnetic field at the location of the coil.

Cutnell, Physics, 8th edition Physics I & II PHY 101 10 nment Chapter 22, Problem 21 rotating n a uniform magnetic field. At t s the normal to the (olis per endicular to the mig etic eld. At t 002?the normal makes an and ed 44 ith the field beause them hn ude e e e ot th et re ete A d cular coil 960 tu ns, radius 0.0 3 m average emf of magnitude 0.071 V is induced in the coil. Find the magnitude of the magnetic field at the location of the coil. Number The number of signticant digits is set to 3; the tolerance is +-1 in the 3rd Significant digit click if you would like to Show Work for this question: Open Show Work Question Attempts: 0 of 3 used SA FORLATER 201 Type here to search

Explanation / Answer

Avg EMF is given by:

EMF = -N*d(phi)/dt

phi = B.A = B*A*cos theta

So,

EMF = -N*A*B*(cos theta2 - cos theta1)/dt

|B| = EMF*dt/(N*A*(cos theta2 - cos theta1))

theta1 = 90 deg

theta2 = 360*(1/8) = 45 deg

Using given values

|B| = 0.071*0.028/(960*pi*0.083^2*(cos 45 deg - cos 90 deg))

|B| = 1.35*10^-4 T

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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