Question
Question: The dipole moment of a short bar magnet is 1.25 A-m<sup>2</sup>. The magnetic field on its axis at a...
The dipole moment of a short bar magnet is 1.25 A-m2. The magnetic field on its axis at a distance of 0.5metre from the centre of the magnet is
A

B
4×10−2 Newton / amp - metre
C

D
6.64×10−8 Newton / amp - metre
Answer

Explanation
Solution
B=4πμ0d32M=10−7×(0.5)32×1.25=2×10−6 N/A−m