Assertion: oscilloscope | /r/CapableOf | use a cathode-ray tube
Facets:
value: to project a beam of electrons
type: PURPOSE
Source sentences:
text: The common cathode-ray oscilloscope uses a cathode-ray tube to project a beam of electrons onto the interior of a nearly flat surface surface of the tube, which is coated with a material which fluoresces when struck by the moving electrons.