back to directory
NEET PHYSICSWAVEMedium

Question

An organ pipe filled with a gas at 27C27^\circ\text{C} resonates at 400 Hz400\text{ Hz} in its fundamental mode. If it is filled with the same gas at 90C90^\circ\text{C}, the resonance frequency at the same mode will be:

A

420 Hz420\text{ Hz}

B

440 Hz440\text{ Hz}

C

484 Hz484\text{ Hz}

D

512 Hz512\text{ Hz}

Step-by-Step Solution

The fundamental frequency of an organ pipe is directly proportional to the speed of sound in the gas (fvf \propto v). The speed of sound in an ideal gas is given by v=γRTMv = \sqrt{\frac{\gamma RT}{M}}, which means vTv \propto \sqrt{T}, where TT is the absolute temperature. Therefore, fTf \propto \sqrt{T}. Given: Initial temperature, T1=27C=27+273=300 KT_1 = 27^\circ\text{C} = 27 + 273 = 300\text{ K} Initial frequency, f1=400 Hzf_1 = 400\text{ Hz} Final temperature, T2=90C=90+273=363 KT_2 = 90^\circ\text{C} = 90 + 273 = 363\text{ K} Final frequency, f2=?f_2 = ? Using the relation f2f1=T2T1\frac{f_2}{f_1} = \sqrt{\frac{T_2}{T_1}}: f2=400×363300f_2 = 400 \times \sqrt{\frac{363}{300}} f2=400×1.21f_2 = 400 \times \sqrt{1.21} f2=400×1.1=440 Hzf_2 = 400 \times 1.1 = 440\text{ Hz}. The resonance frequency at 90C90^\circ\text{C} will be 440 Hz440\text{ Hz}.

Exam Context & Concepts Covered

This question aligns with the NEET PHYSICS syllabus, specifically targeting concepts from WAVE. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

PHYSICSWAVEfilledcirctextcresonatesfundamentalfilled

More WAVE Questions

View all

If the initial tension on a stretched string is doubled, then the ratio of the initial and final speeds of a transverse wave along the string is:

A.$1:2$
B.$1:1$
C.$\sqrt{2}:1$
D.$1:\sqrt{2}$
EasySolve

When a string is divided into three segments of lengths $l_1, l_2$ and $l_3$, the fundamental frequencies of these three segments are $\nu_1, \nu_2$ and $\nu_3$ respectively. The original fundamental frequency ($\nu$) of the string is:

A.$\sqrt{\nu}=\sqrt{\nu_1}+\sqrt{\nu_2}+\sqrt{\nu_3}$
B.$\nu=\nu_1+\nu_2+\nu_3$
C.$\frac{1}{\nu}=\frac{1}{\nu_1}+\frac{1}{\nu_2}+\frac{1}{\nu_3}$
D.$\frac{1}{\sqrt{\nu}}=\frac{1}{\sqrt{\nu_1}}+\frac{1}{\sqrt{\nu_2}}+\frac{1}{\sqrt{\nu_3}}$
MediumSolve

Two periodic waves of intensities $I_1$ and $I_2$ pass through a region at the same time in the same direction. The sum of the maximum and minimum intensities is:

A.$I_1+I_2$
B.$(\sqrt{I_1}+\sqrt{I_2})^2$
C.$(\sqrt{I_1}-\sqrt{I_2})^2$
D.$2(I_1+I_2)$
EasySolve

The two nearest harmonics of a tube closed at one end and open at the other end are $220 \text{ Hz}$ and $260 \text{ Hz}$. What is the fundamental frequency of the system?

A.$10 \text{ Hz}$
B.$20 \text{ Hz}$
C.$30 \text{ Hz}$
D.$40 \text{ Hz}$
MediumSolve

A transverse wave propagating along the $x$-axis is represented by: $y(x,t) = 8.0\sin(0.5\pi x - 4\pi t - \frac{\pi}{4})$, where $x$ is in meters and $t$ in seconds. The speed of the wave is:

A.$4\pi \text{ m/s}$
B.$0.5 \text{ m/s}$
C.$\frac{\pi}{4} \text{ m/s}$
D.$8 \text{ m/s}$
EasySolve

The fundamental frequency in an open organ pipe is equal to the third harmonic of a closed organ pipe. If the length of the closed organ pipe is $20 \text{ cm}$, the length of the open organ pipe is:

A.$13.2 \text{ cm}$
B.$8 \text{ cm}$
C.$12.5 \text{ cm}$
D.$16 \text{ cm}$
MediumSolve

The number of possible natural oscillations of the air column in a pipe closed at one end of a length of $85 \text{ cm}$ whose frequencies lie below $1250 \text{ Hz}$ is: (velocity of sound $340 \text{ ms}^{-1}$)

A.4
B.5
C.7
D.6
MediumSolve

A source of unknown frequency gives $4 \text{ beats/s}$ when sounded with a source of known frequency $250 \text{ Hz}$. The second harmonic of the source of unknown frequency gives five beats per second when sounded with a source of frequency $513 \text{ Hz}$. The unknown frequency is

A.$254 \text{ Hz}$
B.$246 \text{ Hz}$
C.$240 \text{ Hz}$
D.$260 \text{ Hz}$
MediumSolve

This neet physics practice question is part of the TopperSquare free question bank. TopperSquare offers 15,000+ chapter-wise NEET MCQs across Physics, Chemistry, and Biology with detailed step-by-step explanations, full mock tests, NEET PYQs (2010–2024), and an AI-powered performance analytics dashboard. browse all neet practice questions → · practice physics sets →