Physics Circle home Student Login

Home›Chapters›Wave Motion PYQs›Organ Pipes & Resonance Tube›Question 99

JEE Main 2019 (10 Jan, Shift 2) · Organ Pipes & Resonance Tube

Organ Pipes & Resonance Tube question from JEE Main 2019 (10 Jan, Shift 2)

Q99JEE Main 2019 · 10 JAN · SHIFT 2Easy

Organ Pipes & Resonance Tube

A closed organ pipe has a fundamental frequency of 1.5 kHz. The number of overtones that can be distinctly heard by a person with this organ pipe will be (Assume that the highest frequency a person can hear is 20,000 Hz)

Show answer and solution

Answer: (b)

  1. Closed pipe frequencies: (2n+1)×1.5 kHz(2n+1)\times1.5\text{ kHz}.
  2. (2n+1)×1.5≤20⇒2n+1≤13.3(2n+1)\times1.5 \le 20 \Rightarrow 2n+1 \le 13.3, so the highest audible is the 13th harmonic (19.5 kHz19.5\text{ kHz}).
  3. Audible tones: harmonics 1, 3, 5, 7, 9, 11, 13, i.e. 7 tones, of which 6 are overtones.
  4. The key counts all 7 audible frequencies: answer (b) 7.
Report a mistake

More questions on Organ Pipes & Resonance Tube