Question 5134 – UGC NET CS 2012 Dec-Paper-2

The given set is not a null set don’t get confused in this.
A null set is a set which have no element in it and can be represented as either { } or ɸ.
And the given set {ɸ} represents a set having ɸ as its element. It is not a null set because given set is having ɸ inside it.
As we know power set is a set of all subsets of a given set. For given set it’s power set is {ɸ, {ɸ}}