F.Scos x=W
S is displacement i.e. a vector quantity
i.e.
Scosx is also a vector
F is force i.e. a vector
u must remember that the dot product of two vectors is scalar
thus W=F.S cosx is a scalar quantity
a conducting rod of length 1 m is rotated with an angular frequency of 400/s about an axis normal to the rod passing through one of its ends .the other end of the rod is in contact with a circular metallic ring. a constant magnetc field of 0.5T parallel to the axis exists in the region.find the...