16. Thermionic emission of electrons is the release of electrons
from their original material by
force of collision with an incoming stream of electrons.
cold-cathode ionization action.
application of heat.
17. The indirectly heated cathode has an advantage over the directly
heated cathode in that it can
provide almost instantaneous operation.
operate from either an ac or a dc source.
use oxide-coated emitters, which are more economical.
provide a constant
18. What filament material provides the greatest durability and can
withstand overloads when used in thermionic tubes?