Question Detail
Question
A magnetic induction of 20μT is applied to a long straight current carrying wire of radius 120mm. Find the current in the wire. (μ₀ = 4π×10^-7 Tm/A)
Correct Answer
Option C is the correct answer.
Detailed Explanation
B = μ₀I/(2πr) => I = 2πrB/μ₀ = 2π × 0.12 × 20×10^-6 / (4π×10^-7) = 12A.
Hint
Magnetic field around a long straight wire: B = μ₀I/(2πr).