When white light is incident on an object and it absorbs all the component colors and reflects none of them,what color does the object appear to be?

What is the method of obtaining various colors by mixing primary colors in appropriate proportions called?

Why is the colour of the sky blue?

Which optical phenomenon is responsible for the formation of a mirage?

$A$ prism $ABC,$ with base $BC,$ is placed in four different orientations as shown. $A$ narrow beam of white light is incident on the prism as shown. In which of the following cases,after dispersion,the third colour from the top corresponds to the colour of the sky?

$A$ student sitting on the last bench can read the letters written on the blackboard but is not able to read the letters written in his textbook. Which of the following statements is correct?