A magnetic field ` vec(B) = B_(0)hat(j)` , exists in the region `a ltxlt2a` , and vec(B) = -B_(0) hat(j)` , in the region `2a lt xlt 3a`, where `B_(0)` is a positive constant . A positive point charge moving with a velocity `vec(v) = v_(0) hat (i)` , where `v_(0) is a positive constant , enters the magnetic field at `x= a` . The trajectory of the charge in this region can be like
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The correct Answer is:
A
Use the vector form of `B` and `v` in the formulae ` vec(F) = q(vec(v)xx vec(B)) ` to get instaneous direction of force at ` x= aand x = 2a` .
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