10.2 Properties of Cathode rays
Aim: to determine some of the properties of the rays which come from the cathode of a discharge tube. Equipment
* Two power packs
* Two plug-plug leads
* One pair of magnets
* Induction coil
* Four plug-clip leads
* Discharge tubes (Maltese cross, electric plates, rotating wheel, screen display) Theory:
This experiment is designed to show you the properties of cathode rays as discovered by Sir William Crookes. Method:
1. Connect the power pack to the induction coil and set it to 6 volts. Adjust the points of the induction coil so that a stong steady spark is being produced. 2. Connect the terminals of the induction coil to the discharge tube containing the Maltese cross. Observe the end of the tube containing the cross when it is down and again when up. 3. Replace the Maltese cross tube with the tube containing electric plates and connect the terminals of the plate to it high DC voltage supply. Observe the effects of the electric field on the cathode rays. 4. Connect the tube with the fluorescent screen display to the induction coil and record the effect of placing a set of bat magnets around the cathode rays 5. Finally, attach the tube containing the glass wheel on tracks to the induction coil and observe the effects that the cathode rays have on the wheel when the tube is horizontal Safety note
* X-rays are produced when the discharge tube is connected to the induction coil. It is however the cathode rays hitting the glass or metal within the discharge tube that creates the x-rays and not the induction coil. If the experiment uses a minimum operating voltage these x-rays will be of low energy and are significantly reduced after passing through the glass. * We need to deal with induction coils with exteme care because of the high voltages associated with them.
2. What is...
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