This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: calculation of the e/m ratio . ________________________________________________________________________ Introduction 1.1 Electron are emitted at the cathode of a CRT and accelerated through an accelerating DC voltage V a towards the screen. In addition a small transverse (AC) voltage acts across the XX / plates. . Once the electron leaves the plate region its velocity ‘v ‘is constant and makes angle & with Z-axis. The component of it’s velocity along Z-axis is v || =v cos & & ±² When the AC deflecting velocity is switched on, different electrons receive varying velocity v ³ and hence a line gets formed on the CRT screen. fig 1 I.2 When the CRT is placed along the axis of the solenoid then there is a magnetic field B= ± o n I (along the axis of the solenoid) which acts on the electron. Here n=number of turns per unit length of the solenoid and I=current in the solenoid, length of the solenoid and I=current in the solenoid....
View Full Document
- Fall '09
- Electron, Magnetic Field, Cathode Ray Tube, e/m, CRT power supply