Elektron zaryadi ishorasi, zanjirdagi kuchlanishni rostlovchi elektr asbob, zaryadlar orasidagi ta’sir kuchi kim tomonidan aniqlangan, zanjirdagi tok kuchi uning qarshiligiga qanday bog’langan, tok kuchi birligi, zanjirdagi tok kuchi va kuchlanishni rostlovchi elektr asbob, tok so’zining ma’nosi, iste’molchilarning ketma-ket va parallel ulanishi nima deyiladi