Medium MCQ +4 / -1 PYQ · JEE Mains 2020

In a resonance tube experiment when the tube is filled with water up to a height of 17.0 cm from bottom, it resonates with a given tuning fork. When the water level is raised the next resonance with the same tuning fork occurs at a height of 24.5 cm. If the velocity of sound in air is 330 m/s, the tuning fork frequency is :

  1. A 2200 Hz Correct answer
  2. B 3300 Hz
  3. C 1100 Hz
  4. D 550 Hz

Solution

${l_1} = l - 17$<br><br>${l_2} = l - 24.5$<br><br>We know, $v = 2f({l_1} - {l_2})$<br><br>$\Rightarrow$ $330 = 2 \times f \times [(f \times [(l - 17) - (l - 24.5)] \times 10^{ - 2}$<br><br>$\Rightarrow$ $165 = f \times 7.5 \times {10^{ - 2}}$<br><br>$\Rightarrow$ $f = {{165 \times 1000} \over {7.5}}$<br><br>$\Rightarrow$ $f = 2200\,Hz$

About this question

Subject: Physics · Chapter: Waves · Topic: Wave Motion and Types

This question is part of PrepWiser's free JEE Main question bank. 88 more solved questions on Waves are available — start with the harder ones if your accuracy is >70%.

Drill 25 more like these. Every day. Free.

PrepWiser turns these solved questions into a daily practice loop. Chapter-wise drills, full mocks, AI doubt chat. No auto-renew.

Start free →