Question

Aproton enters a magnetic field of flux density 1.5 Wb/m² with a speed of 2x 10⁷ m/s at angle of 30° with the field. The force on the proton will be-

(a) 0.24 x 10^-12 N 

(b) 2.4 x 10^-12 N 

(c) 24 x 10^-12 N 

(d) 0.024 x 10^-12 N

Answer 1

(b) 2.4 x 10^-12 N

F = Bqv sin θ =1.5 x 1.6 x 10^-19 x 2 x 10⁷ x sin 30° 

= 2.4 x 10^-12 N