Circuit LED

2) Activitat

R=V/I  R=9/30=0,3 KΩ= 300Ω

3) Activitat

Vr1= Vt-Vled= Vr1= 9-2=7V
I=V/R= 7/350=0,02Am·1000=20Am
Vr2=Vt-Vled2=Vr2=9-2-2=5V: 500=0,01A=10mA