Cramster.com - Homework Solutions, Lecture Notes, Exams, and Free Online Homework Help
Sign Up Now! Login Customer Support Cramster Blog
McAfee Secure sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams
Problem Solved.
    Home    
    Homework Help    
   Answer Board   
    Resources (Beta)    
   
You Are Here: Home > Answer Board > Physics > Topic: hw help
Member's Topic Headline:

hw help

Know the answer? Have a better solution? Share it.
Sign Up Now for FREE!
Join the thousands of students
getting ahead in their classes.
Member Testimonials

Question:

Advertisement:
Answer | Ask New Question | Customize Profile | Leaderboards | 
FAQ

Member's Avatar
Scholar
Karma Points: 200
Respect (100%):
Date Posted: 7/24/2008 1:51:14 PM  Status: Live
hw help
Course Textbook Chapter Problem
General Physics N/A N/A N/A
Question Details:
Two long, straight wires are separated by 0.12 m. The wires carry currents of 7.5 A in opposite directions, as the drawing indicates.

(a) Find the magnitude of the net magnetic field at the point A.
Answer in T

(b) Find the magnitude of the net magnetic field at the point B.
 Answer in T
Bonus Point Alert! Earn +4 additional karma points for helping this annual member.

Answers:

Member's Avatar
Mentor
Karma Points: 504
Date Posted: 7/24/2008 2:26:53 PM  Status: Live
Asker's Rating: Helpful   
Response:
Use the right hand rule to determine the direction of the magnetic field in the two wires.  Since the current has the same magnitude but different directions, at the center point, the net magnetic field will be zero.

a)  Use Ampere's Law to calculate the net field at point A.



You will need to calculate the field contribution from both wires and subtract the contributions together. B = B1 - B2.

For the wire closest to point A, I calculated B1 = 5 x 10-5 T.  For the second wire, I calculated B2 = 1 x 10-5 T.  Subtract B2 from B1 for a total of:  B = 4 x 10-5 T directed out of the plane.  You should check these calculations.

b) For the point in the middle, the net B field will be 0 T as the oppositely directly field components will cancel.  You could calculate this using the same procedure as before, but using symmetry we can obtain the same result.




By reading or posting messages on these forums, you are agreeing to the Answer Board's Terms of Service and Conduct (TSC).


About Cramster | Terms of Use | Privacy Policy | Contact Us | Press Room | Site Map | Support | Anti-Cheating Policy

Cramster.com is not affiliated with any publisher. Book covers, title and author names appear for reference only.
Copyright © 2008 Cramster, Inc.