A compass needle placed east of a long straight conductor experiences a magnetic field of

PHYSICS · Multi-part · AP · Physics 2: Algebra-based · Magnetism and Electromagnetism · Magnetism and Electromagnetism

Problem

A compass needle placed

4.0\,\text{cm}

east of a long straight conductor experiences a magnetic field of

6.4 \times 10^{-5}\,\text{T}

. Assume the conductor is infinitely long and carries a steady current. Take

\mu_0 = 4\pi \times 10^{-7}\,\text{T\,m\,A}^{-1}

. (i) Calculate the current in the conductor. (ii) Keeping the current unchanged, determine the magnetic field when the compass is moved to a point

2.0\,\text{cm}

from the conductor.