I know from ${\bf F}=q({\bf v}\times {\bf B})$ the force is perpendicular to displacement and so work by magnetic field is always zero. But then how is that a magnet is able to displace any magnetic or metallic object and still cause no work because the motion of the object should be in the direction of force. So what is causing this object to move and which force is doing this work?
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6$\begingroup$ Does this answer your question? How can magnets be used to pick up pieces of metal when the force from a magnetic field does no work? $\endgroup$– Manas DograCommented Jul 15, 2020 at 4:27
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$\begingroup$ @ManasDogra The top rated answer in the link is wrong. $\endgroup$– my2ctsCommented Jul 15, 2020 at 8:55
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By definition a magnetic field does not do work. As soon as things move the electric field comes into play and this does the work. While the distinction between electric and magnetic force is useful in static cases, you will always have to consider both to understand a dynamic case.