Question

question: which among these is an element in a triode but not a diode? answer options: select one of four grid vacuum cathode anode

Explanation:

A diode has two electrodes: cathode and anode, and may have a vacuum (in vacuum diodes). A triode, in addition to cathode and anode, has a control grid. So the element present in triode but not diode is Grid.

Answer:

Grid