Sorry, but while going through the article on magnetism in wikipedia I read the following which i couldn't not catch it. When a charged particle moves through a magnetic field B, it feels a force F given by the cross product: F= q V x Bwhere is the electric charge of the particle is the velocity vector of the particle is the magnetic field. Because this is a cross product, the force is perpendicular to both the motion of the particle and the magnetic field. It follows that the magnetic force does no work on the particle; it may change the direction of the particle's movement, but it cannot cause it to speed up or slow down. This might give you pause: Simple bar magnets seem to be entirely able to pick up small metal objects, which certainly seems to require that they do work on those objects. As David Griffiths points out in his textbook Introduction to Electrodynamics, this law is absolute -the magnetic field doesn't do any work. However, quite like the normal force of an inclined plane, which also can't do work, the magnetic field can redirect the efforts of existing forces, and then those forces can indeed do work in the relevant direction. I am not able to understand the underlined lines. I do not know about which "existing forces" is he talking about; and the same applies to "those forces".I will really appreciate the help.Thanks in advance.