Question

write the expression for lorentz force acting on a charged particle?

Answer 1

Solution :F→=q(V→×B→)F→=q(V→×B→)(i) F→F→ is perpendicular to both V→V→ and B→B→ .If ds→ds→ is the instantaneous displacement of the change ds→ds→ is also perpendicular to F→F→Work done by this force = increase in kinetic energyw=F→.ds→w=F→.ds→=Fscos90∘=Fscos⁡90∘But cos90∘=0cos⁡90∘=0w=0w=0Hence increase in kinetic energy is zero.(ii) power = F→.v→F→.v→=Fvcos90∘=Fvcos⁡90∘=0=0Power =0