Current required in a long wire

  • Thread starter Thread starter rwilson5
  • Start date Start date
  • Tags Tags
    Current Wire
Click For Summary
To determine the required current in a long straight wire to generate a magnetic field with an amplitude corresponding to a flux density of 100 mW/cm² at a distance of 1mm, the magnetic field amplitude was calculated to be 2.89 x 10^-6 T. The relevant equations involve the relationship between electric field (E), magnetic field (B), and intensity (I) in electromagnetic waves. The discussion highlights uncertainty in the approach and seeks guidance on resolving the issue. Clarification on the calculations and the application of the equations is requested to ensure accurate results. Understanding these principles is essential for solving the problem effectively.
rwilson5
Messages
1
Reaction score
0

Homework Statement



Determine the amplitude of a magnetic field in an electromagnetic wave that carries a flux density of 100 mW/cm2. How much current would be required in a long straight wire so that the magnetic field if this same amplitude would be generated at a distance of 1mm from the wire.

Homework Equations



$$B_0=\frac{E_0}{c}=\frac{1}{c}\sqrt{\frac{2I}{c\epsilon_0}}$$

The Attempt at a Solution



I'm not sure how to get at this one. I got that $$B_0=2.89 \cdot 10^{-6} T.$$ Just a touch in the right direction would be awesome.
 
Physics news on Phys.org
The approach looks fine, and a computer can check the numerical value. Where is the problem?
 
Thread 'Correct statement about size of wire to produce larger extension'

Thread 'Correct statement about size of wire to produce larger extension'

The answer is (B) but I don't really understand why. Based on formula of Young Modulus: $$x=\frac{FL}{AE}$$ The second wire made of the same material so it means they have same Young Modulus. Larger extension means larger value of ##x## so to get larger value of ##x## we can increase ##F## and ##L## and decrease ##A## I am not sure whether there is change in ##F## for first and second wire so I will just assume ##F## does not change. It leaves (B) and (C) as possible options so why is (C)...
View full post »

Similar threads

Current in circular wire surrounding infinite solenoid in a circuit
  • · Replies 7 ·
Replies
7
Views
1K
Induction heat flux density induced by wire in a slab
  • · Replies 0 ·
Replies
0
Views
939
Force between two halves of a current carrying hollow cylinder
  • · Replies 3 ·
Replies
3
Views
418
Flux between two current-carrying wires
  • · Replies 8 ·
Replies
8
Views
3K
The distance where the magnetic field of two wires is zero
  • · Replies 2 ·
Replies
2
Views
4K
Poynting vector of current carrying wire
  • · Replies 8 ·
Replies
8
Views
5K
Effect of different magnetic fields on a magnetic dipole
  • · Replies 25 ·
Replies
25
Views
2K
Does a Bent Wire Affect Induction Calculations?
  • · Replies 7 ·
Replies
7
Views
2K
How Does a Magnetic Field Affect a Wire Carrying Current?
  • · Replies 2 ·
Replies
2
Views
1K
Induced current in a loop of wire when straight wire is cut
  • · Replies 3 ·
Replies
3
Views
5K