Question

(10%) Problem 7: In a mass spectrometer, a specific velocity can be selected from a distribution by injecting charged particles between a set of plates with a constant electric field between them and a magnetic field across them (perpendicular to the direction of particle travel). If the fields are tuned exactly right, only particles of a specific velocity will pass through this region undeflected. Consider such a velocity selector in a mass spectrometer with a 0.095 T magnetic field.

What electric field strength, in volts per meter, is needed to select a speed of 4.1 x 10^6 ms?

Answer 1

The strength of electric field is
`3.9 * 10^(5)`
`(V)/(m)`

Step-by-step explanation:

Given:

Magnetic field
`B = 0.095` T

Speed of particle
`v = 4.1 * 10^(6)`
`(m)/(s)`

Here we equate two forces

`F_(E) = F_(B)`

`qE = qvB`

`E = vB`

For finding electric field strength,

`E = 4.1 * 10^(6) * 0.095`

`E = 3.9 * 10^{}`
`(V)/(m)`

Therefore, the strength of electric field is
`3.9 * 10^(5)`
`(V)/(m)`