an open organ pipe has afrequency f. if half part of the organ pipe is dipped in water then what will be the change in frequency?

freq. remain same

When you place the pipe in water the organ pipe acts as a closed one. 

Initially frequency of the organ pipe is f = V/2L

When you place in water with only half the length,

the frequency becomes f = V/4L/2 = V/2L 

Hence frequency doesnt change

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