I have to do a lab on cathode ray tubes. Can you explain to me how the cathode ray tubes work? And can you mention the voltages involved, what they do, and what effect varying these voltages has on the electron beam.

Answer 1

I suggest you start here:

http://electronics.howstuffworks.com/tv3.htm

There are several pages that you will have to access one at a time by clicking at the bottom of each page.

For about 60 years, cathode ray tubes were what you looked at when watching TV or a computer monitor. They are still used for oscilloscopes and many other visual display devices. They are becoming obsolete as more efficient high-resolution visual display devices such as liquid crystal screens have been developed.