1) A pipe open at both ensa has a fundamental frequency f in air. The pipe is dipped vertically in the water, so that half of it is in water, The fundamental frequency of the air column is now A) f2 B) 3f4 C) 2f D) f Answer: Option DExplanation:The fundamental frequency of open pipe f=v2l Now, after half-filled with water it becomes a closed pipe of length l/2 The fundamental frequency of this closed pipe. f′=v4(l2) = v2l=f