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. 4 N in direction
B. 8 N in Y direction
C. 8 N in Z direction
D. 8 N in - Z direction

Answer

d

Explanation

Force in a magnetic field region ,
`vecF = Q (vec v xx vecB)`
` = - 2 xx 10^(-6) [10 ^(6) ( 2 hat I + 3 hat j) xx 2 hat j]`
` = - 2 [4 hat I xx hat j) + 6 ( hat j xx hat j ) ] = - hat k " " (. :, hat j xx hat j = 0 )`
`vec F = - 8 hat k N`