MCQ
A glass tube $1.5 m$ long and open at both ends, is immersed vertically in a water tank completely. A tuning fork of $660 Hz$ is vibrated and kept at the upper end of the tube and the tube is gradually raised out of water. The total number of resonances heard before the tube comes out of water, taking velocity of sound air $330 m/sec$ is
  • A
    $12$
  • $6$
  • C
    $8$
  • D
    $4$

Answer

Correct option: B.
$6$
b
(b) Suppose $N$ resonance occurred before tube coming out.

Hence by using $l = \frac{{(2N - 1)v}}{{4n}}$

==>$1.5 = \frac{{(2N - 1) \times 330}}{{4 \times 660}}$ ==> $N \approx 6$.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

The position of a particle moving along the $X-$axis at certain times is given below :Which of the following describes the motion correctly

$\begin{array}{|c|c|c|c|c|} \hline t( s ) & 0 & 1 & 2 & 3 \\ \hline x ( m ) & -2 & 0 & 6 & 16 \\ \hline \end{array} $

Figure shows two cases. In first case a spring (spring constant $K$ ) is pulled by two equal and opposite forces $F$ at both ends and in second case is pulled by a force $F$ at one end. Extensions $(x)$ in the springs will be
A rocket is launched normal to the surface of earth, away from the Sun, along the line joining the Sun and the Earth. The Sun is $3 \times 10^5$ times heavier than the Earth and is at a distance $2.5 \times 10^4$ times larger than the radius of the Earth. The escape velocity from Earth's gravitational field is $\mathrm{ve}_{\mathrm{e}}=11.2 \mathrm{~km} \mathrm{~s} \mathrm{~s}^{-1}$. The minimum initial $\left(\mathrm{v}_{\mathrm{s}}\right)$ required for the rocket to be able to leave the Sun-earth system is closest to

(Ignore the rotation and revolution of the Earth and the presence of any other planet)

When water droplets merge to form a bigger drop:
If the equation for the displacement of a particle moving on a circular path is given by $(\theta) = 2t^3 + 0.5$, where $\theta$ is in radians and $t$ in seconds, then the angular velocity of the particle after $2\, sec$ from its start is    ......... $rad/sec$
A particle moves with a velocity $6\hat i - 4\hat j + 3\hat k\,m/s$ under the influence of a constant force $\overrightarrow F = 20\hat i + 15\hat j - 5\hat k\,N.\,$ The instantaneous power applied to the particle is......... $J/s$
A length $5.997 m$ rounded off to three significant figures is written as .......... $m$
The angle between $\vec{\text{A}}=\hat{\text{i}}+\hat{\text{j}}$ and $\vec{\text{B}}=\hat{\text{i}}-\hat{\text{j}}$ is
Which of the following statement is not correct :
A simple pendulum is taken from the equator to the pole. Its period