Question

In a pipe open at both the ends the distance between node and antinode is

Answer 1

$\frac{\lambda}{4}$

Answer 2

For a standing wave, the distance between a node and the adjacent antinode is always $\frac{\lambda}{4}$. In a pipe open at both ends, the standing wave pattern has antinodes at both ends and nodes in between, so the distance between any node and its adjacent antinode is $\frac{\lambda}{4}$.