STATEMENT – I: In standing wave the phase difference between the two particles can be zero or $\pi$ only.

STATEMENT – II: Phase difference between the two particles for all the waves is given by $\Delta \varphi =\frac{2\pi }{\lambda }\Delta x$

STATEMENT – I is True, STATEMENT – 2 is True; STATEMENT – 2 is NOT a Correct explanation for STATEMENT – 1 

STATEMENT – I is True, STATEMENT – 2 is True; STATEMENT – 2 is a correct explanation for STATEMENT – 1 

STATEMENT – 1 is True, STATEMENT – 2 is False

STATEMENT – 1 is False, STATEMENT – 2 is True