Condutores e Isolantes - Nelson Cavalcante - 9º Ensino Fundamental - OBMEP

Whole-channel inclusion: Portal da Física OBMEP is an honest teaching channel (title sample + 3 transcripts read: All sampled videos lack transcripts, so the verdict relies on the title-sample assessment indicating consistent physics teaching content with no entertainment or marketing.); this title passed a strict title check (sonnet) after a labelling pass.

A 12-minute video from Portal da Física OBMEP: “Condutores e Isolantes - Nelson Cavalcante - 9º Ensino Fundamental - OBMEP”.

Video by Portal da Física OBMEP, played through YouTube's embedded player.