how does magnetic force in one frame is converted into electric force in other

Question

roadjester · Answer

$\huge gradient\space\space X \vec E=-{\partial\vec B \over \partial t}$
$\huge gradient\space\space X \vec B=\mu_0 j+\epsilon_0 \mu_0 {\partial\vec E \over \partial t}$

roadjester · Answer

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/maxeq.html

anonymous · Answer

actually the question should have been why is magnetic FIELD in one frame convert to an electric field in a moving frame. For example an electron stationary in a magnetic filed feels no force. Only as it moves relative to  the field does it experience a force.  Maxwell's equations govern this behavior.