1.I=U/R=220V/97欧姆≈2.27A
2.0.1千欧=100欧 U=IR=2.1A*100欧=210V
3.250毫欧=0.25A R=U/I=202V/0.25A=8.8欧
4.I=U/R=(5欧+15欧）除以6V=0.3A