Solution:
All except Radio waves are short wavelength radiations.

Solution:
In the other groups, there is a gap of 2 letters between first and second letters also a gap of 3 letters between second and third letter.

Solution:
All except Nitrogen are used as fertilizers.

Solution:
Kite, Crow and Sparrow are names of the Birds.

Solution:
In all other pairs, second requires the first to function.

Solution:
125 is the only number in the group which is a perfect cube.

Solution:
In all other groups, the first letter occupies the same position from A onward as the second letter occupies from Z backward e.g., D is the fourth letter from the beginning and W is the fourth letter from the end of the alphabet.