Homework_18

# Homework_18 - Nguyen Thanh – Homework 18 – Due Apr 8...

This preview shows pages 1–2. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

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

Unformatted text preview: Nguyen, Thanh – Homework 18 – Due: Apr 8 2008, 7:00 pm – Inst: Weathers 1 This print-out should have 10 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. The due time is Central time. 001 (part 1 of 4) 10 points A cylindrical filament has radius 1 . 42 mm. Its resistance is 1 . 28 Ω and its length is 0 . 507 m. The filament carries a uniform, steady current of 0 . 387 A. The permeability of free space is 4 π × 10- 7 N / A 2 . Find the electric field inside the filament. Correct answer: 0 . 977041 N / C. Explanation: Let : ‘ = 0 . 507 m , R = 1 . 28 Ω , and I = 0 . 387 A . The electric field inside the filament has to point in the direction of the current; the field causes the current to flow. To find the field, first consider the voltage drop across the ends of the wire, V = I R . The electric field inside the filament is E = V ‘ = I R ‘ = (1 . 28 Ω)(0 . 387 A) . 507 m = . 977041 N / C . 002 (part 2 of 4) 10 points Find B at the surface of the filament. Correct answer: 5 . 4507 × 10- 5 T. Explanation: Let : r = 1 . 42 mm = 0 . 00142 m , and μ = 4 π × 10- 7 N / A 2 . Using Ampere’s Law I ~ B · ds = μ I , the magnetic field from a long straight wire is given by B = μ I 2 π r (considering a circular loop around the wire). B = μ I 2 π r = (4 π × 10- 7 N / A 2 )(0 . 387 A) 2 π (0 . 00142 m) = 5 . 4507 × 10- 5 T ....
View Full Document

## This note was uploaded on 10/24/2011 for the course PHYS 2220 taught by Professor Littler during the Spring '00 term at North Texas.

### Page1 / 4

Homework_18 - Nguyen Thanh – Homework 18 – Due Apr 8...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online