When a yellow card is viewed in blue light, It will appear

Analyze the question: A yellow card is lit only by blue light. What colour does the eye see?

Concept: An object's colour depends on which colours of light it reflects and which it absorbs.

• A yellow pigment reflects yellow light (and the nearby red and green). It absorbs the other colours, including blue.
• Blue light contains only blue wavelengths.

Step-by-step solution:

1. The only light falling on the card is blue.
2. The yellow card absorbs blue light, because it reflects only yellow, red and green.
3. With nothing reflected into the eye, the card looks dark.

Answer: The card appears black, which is option A.

Tip: A coloured object viewed in light that contains none of its own colour looks black. For example, a red object in green light looks black, and a yellow object in blue light looks black. Ask yourself, "Is the object's colour present in the light?" If not, the answer is usually black.