Clayton State University

Department of Natural Sciences

July 5, 2007

Physics 1112 – Quiz 8

Name __SOLUTION___________________________________

A certain solenoid has 1000 turns of wire and a length of 10.0 cm.

1. Find the magnetic field inside the solenoid when it carries a current of 2.50 A.

Please specify the direction.

B = m₀ n I = (4p x 10^-7 Tm/A)(1000/(0.100 m))(2.50 A) = 0.0314 T

2. A proton enters the solenoid moving with a speed of 3000 m/s perpendicular to the magnetic field of the solenoid. Find the radius of the proton’s trajectory. Note that the charge of the proton is 1.60 x 10^-19 C and its mass is 1.67 x 10^-27 kg.

R = (mv)/(qB) = (1.67 x 10^-27 kg)(3000)/(1.60 x 10^-19 C)/(0.0314 T) = 0.000997 m