Question

What is the magnetic force on a proton that is moving at 4.5 x 10^7 m/s to the right through a magnetic field that is 1.6 T and pointing away from you? The charge on a proton is 1.6 x 10^-19 C.
A. 1.2 x 10^-19 N down
B. 1.2 x 10^-11 N up
C. 7.2x 10^-7 N up
D. 7.2 x 10^-7 N down

Answer 1

The magnetic force on a charged particle is given as: F = qvBsinФ
B is the magnetic field.
q is the charge on the particle.
v is the velocity of the charged particle.
 Ф is the angle between magnetic field (B) & the velocity of charge (v).


⇒ F = qvb sin Ф

Here, Ф = 90 degree.
and sin 90 = 1
Putting the values in the equation, we get,

F = 1.6 x 10^-19 C × 4.5 × 10^7 m/s × 1.6 T
= 11.52 × 10^-12N
= 1.2 x 10^-11 N up