设带电圆环半径为R，电荷线密度为入=入0sinp，式中入0为一常数。求均匀带电半圆环圆心处的场强。vRO X
设带电圆环半径为R，电荷线密度为入=入0sinp，式中入0为一常数。求均匀带电半圆环圆心处的场强。vRO X
1
设带电圆环半径为R，电荷线密度为入=入0sinp，式中入0为一常数。求均匀带电半圆环圆心处的场强。vRO X