Question

An air column, closed at one end and open at the other, resonates with a tuning fork when the smallest length of the column is $50\,cm$. The next larger length of the column resonating with the same tuning fork is :

• A. 100 cm
• B. 150 cm
• C. 200 cm
• D. 66.7 cm

Answer 1

Answer: (B)

150 cm

Answer 2

First minimum resonating length for closed organ pipe $= \frac{\lambda}{4} = 50 \, cm$
$\therefore$ Next larger length of air column $= \frac{3 \lambda}{4} = 150 \, cm$