The path of a charged particle in a uniform magnetic field depends on the angle `theta` between velocity vector and magnetic field, When `theta is 0^(@) or 180^(@), F_(m) = 0` hence path of a charged particle will be linear. When `theta = 90^(@)`, the magnetic force is perpendicular to velocity at every instant. Hence path is a circle of radius `r = (mv)/(qB)`. The time period for circular path will be `T = (2pim)/(qB)` When `theta` is other than `0^(@), 180^(@) and 90^(@)`, velocity can be resolved into two components, one along `vec(B)` and perpendicular to B. `v_(|/|)=cos theta` `v_(^)= v sin theta` The `v_(_|_)` component gives circular path and `v_(|/|)` givestraingt line path. The resultant path is a helical path. The radius of helical path `r=(mv sin theta)/(qB)` ich of helix is defined as `P=v_(|/|)T` `P=(2 i mv cos theta)` `p=(2 pi mv cos theta)/(qB)` Which particle will have minimum frequency of revolution when projected with the same velocity perpendicular to a magnetic field.A. `Li^(+)`B. electronC. ProtonD. He^(+)`