Question

Mulțumesc anticipat!

Answer 1

$l=20 cm=0,2 m\\\alpha=90^o\\a)F_{elmag}=BIlsin\alpha<=>1=B*10*0,2*1<=>1=2B|:2=>B=0,5 T\\b)F_{elmag}'=BIl_2sin\alpha<=>2=0,5*10*1*l_2<=>2=5l_2|:5=>l_2=0,4 m\\\Delta l=l_2-l=0,4-0,2=0,2m=>$

=>lungimea trebuie marita cu 0,2 m

$c)F_{elmag_2}=BI_2lsin\alpha<=>0,75=0,5*I_2*0,2*1<=>0,75=0,1I_2|:0,1=>I_2=7,5 A$