MHT CET 2026 20th April Morning Shift | Waves Question 7 | Physics

A tuning fork of frequency '$n$' is held near the open end of a tube which is dipped in water and length of the tube is adjusted until resonance occurs. If the two shortest lengths that produce resonance are $l_1$ and $l_2$, the speed of sound in air is (neglect end correction)

$2n(l_2 - l_1)$

$n(l_2 - l_1)$

$\dfrac{n}{2}(l_2 - l_1)$

$\dfrac{2n}{(l_2 - l_1)}$

MHT CET 2026 20th April Morning Shift

MCQ (Single Correct Answer)

-0

The ratio of the speed of sound in helium gas to that in nitrogen gas at $295$ K is ( Ratio of specific heats $\gamma$ for helium is $\dfrac{5}{3}$ and that for nitrogen is $\dfrac{7}{5}$. Molecular weight for helium and nitrogen are $4$ and $28$ respectively.)

$\sqrt{\dfrac{2}{7}}$

$\sqrt{\dfrac{3}{5}}$

$\dfrac{\sqrt{3}}{5}$

$\dfrac{5}{\sqrt{3}}$

MHT CET 2026 20th April Morning Shift

MCQ (Single Correct Answer)

-0

A train is moving towards a stationary observer with speed $34$ m/s. A train sounds a whistle of frequency $450$ Hz. If the speed of sound is $340$ m/s, the frequency heard by the observer in Hz is

$440$

$480$

$500$

$540$

MHT CET 2025 5th May Evening Shift

MCQ (Single Correct Answer)

-0

A person observes two moving trains. First reaching the station and another leaves the station with equal speed of $30 \mathrm{~m} / \mathrm{s}$. If both trains emit sounds of frequency 300 Hz , difference of frequencies heard by the person will be (speed of sound in air $330 \mathrm{~m} / \mathrm{s}$ )

80 Hz

75 Hz

55 Hz

45 Hz

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Some Basic Concepts of Chemistry Atomic Structure States of Matter Thermodynamics Chemical Equilibrium Ionic Equilibrium Liquid Solution Redox Reactions Surface Chemistry Solid State Electrochemistry Chemical Kinetics Nuclear Chemistry

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