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## Homework Statement

Estimate the approximate maximum deflection of the electron beam near the center of a CRT television screen due to the Earth's field. Assume the screen is 20 from the electron gun, where the electrons are accelerated by the following voltages. Note that in color TV sets, the beam must be directed accurately to within less than 1 in order to strike the correct phosphor. Because the Earth's field is significant here, mu-metal shields are used to reduce the Earth's field in the CRT.

By 2.2 kV

## Homework Equations

We know that

eV=Work

KE=(1/2)mv^2

and |q|vB=(mv^2)/R

## The Attempt at a Solution

First I found the speed of the traveling electron(s):

(1.60*10^-19)(2.2*10^3)=(1/2)(9.1*10^-3)(v^2)

v=2.78*10^7

And then when I plug it into the equation

|q|vB=(mv^2)/r

I get a value of deflection to be 3.16 meters, which is not the write answer. I'm not too sure where I went wrong. If anyone could help me out that would be great!