JAMB Physics 2019 Paper

Concept:A pigment is seen by the color of light it reflects, while the light it absorbs is lost.Explanation:White light is made up of red $\text{R}$, green $\text{G}$, and blue $\text{B}$ light.A red pigment reflects $\text{R}$ but absorbs $\text{B}$ and $\text{G}$.A blue pigment reflects $\text{B}$ but absorbs $\text{R}$ and $\text{G}$.When red and blue pigments are mixed, green light is the only primary color absorbed by both pigments — so green disappears.The red pigment still sends $\text{R}$ to the eye, and the blue pigment still sends $\text{B}$ to the eye.Thus, both $\text{R}$ and $\text{B}$ reach the eye from the mixture.Since $\text{R} + \text{B}$ combine additively to give magenta, the mixture appears magenta.Answer:The correct option is D. magenta.