UGC NET November 2017, Q-9, Paper 2

Negation of the proposition ∃ x H(x) is :
(1) ∃x ¬ H(x)
(2) ∀ x ¬ H(x)
(3) ∀ x H(x)
(4) ¬ x H(x)

Ans is  (2) ∀ x ¬ H(x)

negation of (∃ x H(x)) =   ¬ ∃ x H(x)  =  ∀ x ¬ H(x)  (as negation symbol moves from left to right it changes the symbol  ∃ to ∀).