Let r be the distance of a point on the axis of a bar magnet from its center. The magnetic field at r is always proportional to
A. \(\frac {1}{r^2}\)
B. \(\frac {1}{r^3}\)
C. \(\frac {1}{r}\)
D. Not necessarily \(\frac {1}{r^3}\) at all points
Answer:B
Let r be the distance of a point on the axis of a bar magnet from its center. The magnetic field at r is always proportional to
A. \(\frac {1}{r^2}\) B. \(\frac {1}{r^3}\) C. \(\frac {1}{r}\) D. Not necessarily \(\frac {1}{r^3}\) at all points