Question

A straight conductor carries a current of 10 A. The magnetic field at a distance of 2 cm from the wire is: (μ₀ = 4 × 10⁻⁷ T m/A)

• A. 10 T
• B. \(10^{-5}\) T
• C. 10 T
• D. \(10^{-3}\) T

Hint:

To calculate the magnetic field around a current-carrying wire, use the formula \(B = \frac{\mu_0 I}{2 \pi r}\), where \(r\) is the distance from the wire.

Answer 1

The Correct Option is B

The magnetic field \(B\) around a straight current-carrying wire is given by Ampere’s law: \[ B = \frac{\mu_0 I}{2 \pi r} \] where \(I = 10 \, \text{A}\), \(r = 2 \, \text{cm} = 0.02 \, \text{m}\), and \(\mu_0 = 4 \times 10^{-7} \, \text{T m/A}\). Substituting the values: \[ B = \frac{4 \times 10^{-7} \times 10}{2 \pi \times 0.02} = \frac{4 \times 10^{-6}}{0.1256} \approx 3.18 \times 10^{-5} \, \text{T} \]
Final answer
Answer: \(\boxed{10^{-5} \, \text{T}}\)