Q1: If D is the diameter of a circular sewer and D' is the top horizontal diameter of an equivalent egg shaped section, the relationship which holds good, is

ANS:C - D' = 0.84 D

I see, let's consider the given relationship: D′=0.84D This indicates that the top horizontal diameter (D') of an equivalent egg-shaped sewer is 84% of the diameter (D) of a circular sewer. Thank you for providing the correct answer. So, in this case, the relationship that holds good is indeed: D' = 0.84D.