Question

Two small bar magnets are placed in a line with like poles facing each other at a certain distance d apart. If the length of each magnet is negligible as compared to d, the force between them will be inversely proportional to

• A.
• B. $d ^ { 2 }$
• C. $\frac { 1 } { d ^ { 2 } }$
• D. $d ^ { 4 }$

Answer 1

Answer: (D)

$d ^ { 4 }$

Answer 2

$F = \frac { \mu _ { 0 } } { 4 \pi } \left( \frac { 6 M M ^ { \prime } } { d ^ { 4 } } \right)$in end-on position.