Question

电源的电动势E=18 V,内电阻r=1 W,定值电阻器R1=5 W,R3=6 W,水平放置的平行板电容器相距d=2 mm

Answer 1

E=I(r+R1+R2+R)

R=R2*R3/(R2+R3)

U=I*R2

U/d*q=mg

解得

R2=6

m=0.48g