Fill in the blank. The colour in the sequence VIBGYOR that has the least wavelength is …….. .

Which colour of the light has the longest wavelength ?

Which of the following radiation has the least wavelength ?

Fill up the blank spaces appropriately

Mention the colours which have the least and the most wavelength in visible light.

Fill in the blanks to make each of the following a true statement : Each set has at least "………." subsets.