How can you tell when two objects, after being rubbed together, have each acquired an electric charge? How will the magnitude of the charge on each compare with one another? How about the sign of the charge on each?

Why can blue light and yellow light combine to produce white light? question 17 options: they are both primary colors of light. they absorb each other's wavelengths. because blue, yellow, and white are primary colors. they are complementary colors of light.