A vertical pipe open at both ends is partially submerged in water . A tuning fork is unknown frequency is placed near the top of the pipe and made to vibrate . The pipe can be moved up and down and thus length of air column the pipe can be adjusted. For definite lengths of air column in the pipe, standing waves will be set up as a result of superposition of sound waves travelling in opposite directions. Smallest value of length of air column , for which sound intensity is maximum is `10 cm`[ take speed of sound , `v = 344 m//s`].
Answer the following questions.
Frequency of the tuning fork is

Options

A. 3400 Hz
B. 2500 Hz
C. 4300 Hz
D. 1720 Hz

Answer

C