Use the diagram for the next three problems. Electrons traveling at a speed of v 0 = 3 * 10 7 m/s pass through the deflection plates. The electric field between the plates is E = 5000 V/m and spans a distance of
x 1 = 5 cm. The electrons then travel a further distance of x 2 = 40 cm along the x-axis.
-What should the strength of the magnetic field be for the electrons to land at a?
A) 1.67 G
B) 3.33 G
C) 6000 G
D) 3000 G
E) 12000 G

Question

Use the diagram for the next three problems.  Electrons traveling at a speed of v 0 = 3 * 10 7 m/s pass through the deflection plates. The electric field between the plates is E = 5000 V/m and spans a distance of
x 1 = 5 cm. The electrons then travel a further distance of x 2 = 40 cm along the x-axis.
-What should the strength of the magnetic field be for the electrons to land at a?
A) 1.67 G 
B) 3.33 G 
C) 6000 G 
D) 3000 G 
E) 12000 G

Quizplus · Accepted Answer

The strength of the magnetic field should be 1.67 G for the electrons to land at a. This is because the magnetic force on the electrons is equal to the centripetal force required to keep them moving in a circle. The magnetic force is given by F = qvB, where q is the charge of the electron, v is its velocity, and B is the strength of the magnetic field. The centripetal force is given by F = mv^2/r, where m is the mass of the electron, v is its velocity, and r is the radius of the circle. Equating these two forces, we get qvB = mv^2/r. Solving for B, we get B = mv/qr. Substituting the values for m, v, q, and r, we get B = 1.67 G.

Use the Diagram for the Next Three Problems