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The magnetic field a distance 2 cm from a long straight current carrying wire is 2.0 x 10^-5T. The current in the wire is:

Correct answer: C. 2.0A

  • A. 0.13A
  • B. 1.0A
  • C. 2.0A
  • D. 4.0A

Explanation

BL = μ₀ I ⇒ I = BL / μ₀ = 2πr B / μ₀= 2πr B / (4π × 10⁻⁷) = r B / (2 × 10⁻⁷) = (2 × 10⁻²)(2 × 10⁻⁵) / (2 × 10⁻⁷) = 2 A.

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About Electromagnetism

Magnetic flux density and magnetic flux describe the strength of a magnetic field and the field passing through a surface. A charged particle moving through a magnetic field experiences a force perpendicular to its velocity and may follow circular or helical motion, depending on the angle between velocity and field.

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