An air column of length L closed at one end is oscillating in 2nd overtone. Pressure change in air is minimum from the closed end at distance of:

Explanation

When an air column is closed at one end and oscillates in its second overtone, it means that it vibrates in a mode where there are two antinodes (points of maximum displacement) and one node (point of zero displacement) within the column. In this particular case, the fundamental frequency (first overtone) of the closed-end column has one antinode at the open end and one node at the closed end. When the column is in the second overtone, it will have two antinodes and one node. To answer your question, the pressure change is minimal at a node, where the displacement is zero. So, the pressure change is minimal at the closed end of the column, which is at a distance of L from the closed end. So, the correct answer is: D) ZERO The pressure change is minimal (zero) at the closed end of the column in the second overtone mode.