Which one of the following reflects back more sunlight as compared to other?

Which of the following are the primary colours of light?

Which one of the following statements is not correct for light rays ?

Which one of the following statements is correct regarding the travel of a light beam from a rare to a dense medium?

Which of the following does not change when light travels from one medium to another?

Which one of the following colours may be obtained by combining green and red colours ?