# Physics II Lab w answers_Part_22 - I.3 Fig 2 When the...

This preview shows pages 1–2. Sign up to view the full content.

55 Fig 2 I.3 When the magnetic field is present the motion of the electron in the CRT is helical. This is seen as follows. Viewed along the Z-axis with the magnetic field coming out of the page, the magnetic field has the effect of making the electron move in a circular path (fig3). The centripetal force is B v e r v m 2 = -------- ( 1) with v ± r ( is the angular velocity of circular motion =cyclotron frequency) gives m B e = The time period of evolution is B e m 2 T ± = ------------------------------------ (2) Note that T is independent of v Along with the circular motion the electron has a longitudinal velocity v || ² v which transforms the purely rotational motion to helical path (fig 4) fig 4 I.4. The pitch of the helical motion is defined as longitudinal distance moved in one full rotational period i.e. Fig. 3

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
56 I.4. The pitch of the helical motion is defined as longitudinal distance moved in one full rotational period i.e.
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 11/26/2011 for the course PHY 2053 taught by Professor Lind during the Fall '09 term at FSU.

### Page1 / 2

Physics II Lab w answers_Part_22 - I.3 Fig 2 When the...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online