Magnetic Field Surrounding a Straight Conductor

In summary, the conversation discusses the relationship between the angle of ds and r hat, labeled as theta 2, and the angle theta shown in diagram a. It is determined that the angle theta can be found using the definition of the cross product and the fact that angles in a triangle add up to 180 degrees.
  • #1
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Homework Statement
Please see below
Relevant Equations
Please see below
For this problem,
1673658720024.png

Part of the solution is,
1673658743775.png

1673658803501.png

However, would someone please tell me where they got the sine function circled in red from?

Many thanks!
 

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  • #2
Callumnc1 said:
However, would someone please tell me where they got the sine function circled in red from?
You're working with the cross product ##\vec{ds} \times \hat r##. How is the angle between ##\vec{ds}## and ##\hat r## related to the angle ##\theta## shown in diagram ##a##?
 
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  • #3
TSny said:
You're working with the cross product ##\vec{ds} \times \hat r##. How is the angle between ##\vec{ds}## and ##\hat r## related to the angle ##\theta## shown in diagram ##a##?
Thank you @TSny ! I see how they got theta now. :) If we call the angle between ds and r hat as theta 2, then from the definition of the cross product:

dxsin(theta 2) = dxsin(pi/2 - theta) where I found theta 2 using angles in a triangle add up to 180 degrees.
 
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FAQ: Magnetic Field Surrounding a Straight Conductor

What is the magnetic field around a straight conductor?

The magnetic field around a straight conductor is a circular field that surrounds the conductor. This field is generated when an electric current flows through the conductor, following the right-hand rule for its direction.

How is the direction of the magnetic field determined?

The direction of the magnetic field around a straight conductor is determined by the right-hand rule. If you point the thumb of your right hand in the direction of the current, the fingers will curl around the conductor in the direction of the magnetic field lines.

What is the relationship between current and magnetic field strength?

The strength of the magnetic field around a straight conductor is directly proportional to the current flowing through the conductor. This means that as the current increases, the magnetic field strength also increases.

How does the distance from the conductor affect the magnetic field strength?

The magnetic field strength decreases with increasing distance from the conductor. Specifically, the field strength is inversely proportional to the distance from the conductor, meaning that the further you move away from the conductor, the weaker the magnetic field becomes.

What is the formula for calculating the magnetic field around a straight conductor?

The magnetic field (B) at a distance (r) from a long straight conductor carrying a current (I) is given by the formula: B = (μ₀ * I) / (2π * r), where μ₀ is the permeability of free space (4π x 10⁻⁷ T·m/A).

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