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When the current through a circular loop is 7.5 a, the magnetic field at its center is 5.0x10⁻⁴ T. What is the radius (in m) of the loop?

______ m

User Silvana
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Final answer:

Using the formula derived from Biot-Savart law (μ₀I/(2r) = B), we calculate the radius of the circular loop to be approximately 0.0119 meters (11.9 millimeters) when the current is 7.5 A and the magnetic field at the loop's center is 5.0x10⁻⁴ T.

Step-by-step explanation:

When the current through a circular loop is 7.5 A, the magnetic field at its center is measured to be 5.0x10⁻⁴ T. To calculate the radius of the loop, we can use Biot-Savart law or Ampère's law for magnetism. The formula that describes the magnetic field (B) at the center of a circular loop of a single turn, due to a steady current (I), is given by

B = μ₀I/(2r)

where:

  • μ₀ is the permeability of free space (4π x 10⁻⁷ T·m/A),
  • I is the current through the loop,
  • r is the radius of the loop.

To find the radius, we rearrange the equation to solve for r:

r = μ₀I/(2B)

Substituting the given values:

r = (4π x 10⁻⁷ T·m/A x 7.5 A) / (2 x 5.0x10⁻⁴ T)

r = (3.14 x 7.5 x 10⁻⁷ m) / (1.0x10⁻⁴)

After performing the calculation:

r ≈ 0.0119 m

Therefore, the radius of the circular loop is approximately 0.0119 meters or 11.9 millimeters.

User Luke Stoward
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