More rarely, a secondary rainbow is seen, which is a second, fainter arc, outside the primary arc, with colours in the opposite order, that is, with violet on the outside and red on the inside.
An arc of all seven spectral colors appearing in the sky opposite the sun as a result of the refractive dispersion of sunlight in drops of rain or mist.
由于雨滴或雾滴对阳光有折射分光作用，使空中太阳对面出现的一道有七色光谱的弧。
3
The operating principle and the structural features of the newly developed opposite-V type of A. C. arc welding transformer are analyzed in this paper.