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What is the flux density at a point 3 cm from the long straight wire, when there is a current of 25 A in a wire: (u0= 4𝜋 x10-7)

Correct answer: B. 1.67 x 10^-4 T

  • A. 0.23 x 10^-1 T
  • B. 1.67 x 10^-4 T
  • C. 2.99 x 10^-6 T
  • D. 3.63 x 10^-8 T
  • E. 999 x 10^-7 T

Explanation

Magnetic flux density is the number of lines of force that pass through a point on a specific surface. Magnetic Flux Density = Φ/A As, Φ = BA;Thus, Magnetic Flux = BA/A = B (Magnetic Field).The magnetic field at a point of a long straight wire is given as;Given that I = 25 A and r = 0.03m;= 4π × 10^-7 × 25/2π × (0.03) = (50/3) × 10^-5 T = 1.667 × 10^-4 T Hence, the magnetic flux density is 1.667 × 10-4 T.

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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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