[电] radial component of ther electric field
diàn chǎng de jìng xiàng chéng fèn ㄉㄧㄢˋ ㄔㄤˇ ㄉㄜ˙ ㄐㄧㄥˋ ㄒㄧㄤˋ ㄔㄥˊ ㄈㄣˋ