You are here:

# Physics/AC and DC wires placed near together

Advertisement

Question
Dear Sir,
There is an AC current flowing through a wire, so it has an electromagnetic field around it, if we put a wire with DC current  near the AC current wire, what is the effect of these wires on each other? Can we calculate the field? What is the appropriate distance between these two wires? Another, if we shield the wires and put them on a cable tray, has the problem solved?
Best regards

Answer
Placing a DC carrying wire near an AC carrying wire should result in a pulsating force between the wires with a 60 Hertz frequency as the varying magnetic field of the AC wire exerts a varying force in the DC carrying wire and vice versa.
Magnetic Field strength near a long, straight current carrying wire is given by:
B=mu*I/(2*pi*r) where B is the field strengthin Teslas, mu is the the magnetic field constant, I is the current and r is the distance from the center of the wire.
Surrounding each wire with a grounded conducting cylindrical shell should completely shield each wire from the other wire's effects.
Questioner's Rating
 Rating(1-10) Knowledgeability = 10 Clarity of Response = 10 Politeness = 10 Comment No Comment

• Add to this Answer
• Ask a Question

Physics

All Answers

Ask Experts

Volunteer

#### James J. Kovalcin

##### Expertise

I am teaching or have taught AP physics B and C [calculus based mechanics & electricity and magnetism] as well as Lab Physics for college bound students. I have a BS in Physics from the University of Pittsburgh and a Master of Arts in Teaching from same. I have been teaching physics for 34 years. I am constantly updating my skills and have a particular interest in modern physics topics.

©2017 About.com. All rights reserved.

Browse Answers:

[an error occurred while processing this directive]