Step 1: Condition for fundamental mode in closed pipe.
For a closed pipe, the fundamental mode occurs when
\[
L = \frac{\lambda}{4}.
\]
Step 2: Substituting wavelength.
Given \( \lambda = 62 \, \text{cm} \),
\[
L = \frac{62}{4} = 15.5 \, \text{cm}.
\]
Step 3: Conclusion.
The required length of the closed pipe is \(15.5 \, \text{cm}\).