Difference in height between the liquid columns in the vertical arms in situation (ii) will be
dF=(dm)ω2x⇒(dP)A=(ρAdx)ω2x
⇒∫P2P1dP=ρω2∫L0xdx
⇒P2−P1=ρgh1=ρω2L2/2
⇒h1=ω2L22g