hw14 - Physics 21 Fall 2004 Solution to HW-14 28 P 46 An...

This preview shows page 1. Sign up to view the full content.

This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Physics 21 Fall, 2004 Solution to HW-14 28 P 46 An iron core solenoid is 38 cm long, 1.8 cm in diameter, and has 600 turns of wire. A magnetic field of 2.2 T is produced when 48 A ﬂows in the wire. What is the permeability at this high field strength? The expression for the magnetic field in the iron core of the solenoid is B = µnI , where the number of turns per meter is n = N/L . Combining these equations gives B = µN I/L ⇒ µ = BL/N I. Substituting numbers gives µ = 2 . 2 × . 38 600 × 48 = 2 . 90 × 10- 5 Tm / A . 28 P 58 Two large coils of wire, each with N turns carrying a current I and separated by a distance equal to the radius R of the coils, are called Helmholtz coils . (a) Determine B at points x along the line joining their centers. Let x = 0 at the center of one coil, x = R at the center of the other. (b) Plot B versus x from x = 0 to x = R . (c) Determine B on the axis midway between the coils ( x = R/ 2) if R = 20 . 0 cm, I = 35 A, and each coil contains N = 350 turns.= 350 turns....
View Full Document

This note was uploaded on 08/06/2008 for the course PHYS 21 taught by Professor Hickman during the Fall '07 term at Lehigh University .

Ask a homework question - tutors are online