A double U - tube manometer is connected to two liquid lines A and B. Relevant height and specific gravities of the fluids are shown in the given figure. The pressure difference, in head of water, between fluids at A and B is
1
SA hA + S1 hB – S3 hB + SB hB
2
SA hA – S1 hB – S2 (hA – hB) + S3 hB – SB hB
3
SA hA + S1 hB – S2 (hA – hB) – S3 hB + SB hB
4
S1 hB - SA hA + S3 hB + SB hB
5
S1 hB - SA hA - S3 hB + SB hB