Go Back   Physics Help Forum > College/University Physics Help > Advanced Electricity and Magnetism

Advanced Electricity and Magnetism Advanced Electricity and Magnetism Physics Help Forum

Reply
 
LinkBack Thread Tools Display Modes
Old Jan 24th 2010, 10:48 AM   #1
Junior Member
 
Join Date: Jan 2010
Posts: 3
Question Electric Field of a Uniformly Charged Ring

1. The problem statement, all variables and given/known data
A uniformly charged ring of radius 8.1 cm has a total charge of 118 micro Coulombs. The value of the Coulomb constant is 8.98755e9 N M^2/C^2. Find the magnitude of the electric field on the axis of the ring at 1.15 cm from the center of the ring. Answer in units of N/C.

2. Relevant equations
F= k Qq/ r^2
E= kq/r^2


3. The attempt at a solution
I tried subtracting 1.15 cm from 8.1 cm for "r" and plugged that "r" value in the F equation but that answer is wrong. By axis , do they mean horizontally (as in along the diameter) or vertically?Someone said I had to integrate but I dont know what to integrate and from what points.
ILoveCollege is offline   Reply With Quote
Old Jan 24th 2010, 12:09 PM   #2
Senior Member
 
arbolis's Avatar
 
Join Date: Apr 2008
Posts: 815
Originally Posted by ILoveCollege View Post
1. The problem statement, all variables and given/known data
A uniformly charged ring of radius 8.1 cm has a total charge of 118 micro Coulombs. The value of the Coulomb constant is 8.98755e9 N M^2/C^2. Find the magnitude of the electric field on the axis of the ring at 1.15 cm from the center of the ring. Answer in units of N/C.

2. Relevant equations
F= k Qq/ r^2
E= kq/r^2


3. The attempt at a solution
I tried subtracting 1.15 cm from 8.1 cm for "r" and plugged that "r" value in the F equation but that answer is wrong. By axis , do they mean horizontally (as in along the diameter) or vertically?Someone said I had to integrate but I dont know what to integrate and from what points.
Hi ILoveCollege and welcome to PHF!
It's a very common problem. For instance, I found in google Electric Field on the Axis of Charged Ring or Electric Field Along the Axis of a Charged Semicircle or Ring.
Does it make sense?
__________________
Isaac
If the problem is too hard just let the Universe solve it.
arbolis is offline   Reply With Quote
Old Jan 24th 2010, 01:11 PM   #3
Junior Member
 
Join Date: Jan 2010
Posts: 3
Originally Posted by arbolis View Post
Hi ILoveCollege and welcome to PHF!
It's a very common problem. For instance, I found in google Electric Field on the Axis of Charged Ring or Electric Field Along the Axis of a Charged Semicircle or Ring.
Does it make sense?
Yes! Thank You! I also have another question:
"Sketch the gravitational "lines of force" for two equal point masses. These are isomorphic to the electrostatic lines of force of..."
My question is wouldn't two equal "+" point charges produce the same electric field line diagram as two equal "-" point charges?
ILoveCollege is offline   Reply With Quote
Old Jan 24th 2010, 01:17 PM   #4
Senior Member
 
arbolis's Avatar
 
Join Date: Apr 2008
Posts: 815
Originally Posted by ILoveCollege View Post
Yes! Thank You! I also have another question:
"Sketch the gravitational "lines of force" for two equal point masses. These are isomorphic to the electrostatic lines of force of..."
My question is wouldn't two equal "+" point charges produce the same electric field line diagram as two equal "-" point charges?
I'll wait for a more experienced person to answer you well on this question. If both lines of force are indeed isomorphic, then I believe that the answer is yes. Now I don't think that they are isomorphic so I have a doubt.
__________________
Isaac
If the problem is too hard just let the Universe solve it.
arbolis is offline   Reply With Quote
Reply

  Physics Help Forum > College/University Physics Help > Advanced Electricity and Magnetism

Tags
charged, electric, field, ring, uniformly



Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
electric field of a charged disc on an axial point. pranimaboity2050 Electricity and Magnetism 0 Apr 2nd 2015 10:24 AM
Potential of Non-Uniformly Charged Spherical Shell azupol Advanced Electricity and Magnetism 0 Oct 17th 2014 02:07 PM
electric field from a ring ironman1478 Electricity and Magnetism 4 Jan 16th 2010 01:22 PM
Need help with Proper integral of a uniformly charged rod db2dz Electricity and Magnetism 5 Sep 13th 2009 02:32 PM
Charged mass in electric field rice4lifelegit Electricity and Magnetism 2 Sep 7th 2009 06:52 PM


Facebook Twitter Google+ RSS Feed