What is the energy density in the magnetic field 25 cm from a long straight wire carrying a current of 12 A? A)7.3 × 10^-5 J/ m³ B)3.7 × 10^-5 J/ m³ C)3.6 × 10^-4 J/ m³ D)1.2 × 10^-4 J/ m³ E)cannot be determined with the information given

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Quizplus · Accepted Answer

The energy density (u) in a magnetic field is given by u = B²/(2μ₀), where B is the magnetic field and μ₀ is the permeability of free space (4π × 10⁻⁷ T·m/A). For a long straight wire, B = μ₀I/(2πr). Substituting I = 12 A and r = 0.25 m, we find B and then calculate u.

What Is the Energy Density in the Magnetic Field 25