The magnetic force acting on a charged particle of charge `-2 muC` in a magnetic field of `2 T` acting `y` direction, when the particle velocity is `(2i + 3 hat(j)) xx 10^(6) ms^(-1)`, is

Options

A. 8 N in –z direction
B. 4 N in z direction
C. 8 N in y direction
D. 8 N in z direction

Answer

A

Explanation

`vecB = 2 hatj (T)`
`vecv = (2 hati + 3hatj ) xx 10^(6)` m/s
`vecF_(B) = q(vecv xx vecB)`
`implies vecF_(B) = -2 xx 10^(-6) [(2hati + 3hatj) xx 10^(6) xx (2hatj)]`
`= -2 [4hatk + 0] = - 8 hatk(N)`