Thermionic emission (AQA A-Level Physics): Flashcards

Heated metal causes free electrons to gain enough energy to be emitted from surface

Device using thermionic emission to produce electron stream

$\Delta W = eV$

$1.6 \times 10^{-19}$ C

Potential difference electron is accelerated through

KE of electron accelerated across 1 V potential difference

Electrical potential energy → kinetic energy

$\frac{1}{2}mv^2 = eV$

Heat cathode to induce thermionic emission

Accelerates electrons via positive charge & potential difference