MCQ
Vibrating tuning fork of frequency $n$ is placed near the open end of a long cylindrical tube. The tube has a side opening and is fitted with a movable reflecting piston. As the piston is moved through $8.75 cm$, the intensity of sound changes from a maximum to minimum. If the speed of sound is $350 \,m/s. $ Then $n$ is .... $Hz$
  • A
    $500$
  • $1000 $
  • C
    $2000$
  • D
    $4000$

Answer

Correct option: B.
$1000 $
b
(b) When the piston is moved through a distance of $8.75cm$, the path difference produced is $2 \times 8.75\,cm = 17.5\,cm$. This must be equal to$\frac{\lambda }{2}$ for maximum to change to minimum.

$\therefore$ $\frac{\lambda }{2} = 17.5 cm$

==> $\lambda = 35cm = 0.35m$

So, $v = n\lambda $==> $n = \frac{v}{\lambda } = \frac{{350}}{{0.35}} = 1000Hz$

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 density of the atmosphere at sea level is $1.29 \;kg / m ^{3} .$ Assume that it does not change with altitude. Then how high (in $km$) would the atmosphere extend?
The temperature of $5$ moles of a gas which was held at constant volume was changed from ${100^o}C$ to ${120^o}C$. The change in internal energy was found to be $80$ Joules. The total heat capacity of the gas at constant volume will be equal to ...... $J/K$
When a box is in stationary position with respect to train moving with no acceleration, then relative motion is opposed by $...........$ Which provides the same velocity to the box as that of the train, keeping it stationary relative to the train.
Which of the following is not conserved in inelastic collision?
The point on the pressure temperature phase diagram where all the phases co-exist is called
A sample of ideal gas $(\gamma = 1.4)$ is heated at constant pressure. If an $100\, J$ is supplied to gas, the work done by the gas is ...... $J$
A car is moving on an overbridge of radius $R$ with a constant speed $v$. As the car is descending on the overbridge from point $B$ to $C,$ the normal reaction on it due to bridge
A particle moves along $X-$axis as $x = 4(t - 2) + a{(t - 2)^2}$ Which of the following is true ?
In an experiment with a beam balance on unknown mass $m$ is balanced by two known mass $m$ is balanced by two known masses of $16\, kg$ and $4\, kg$ as shown in figure. The value of the unknown mass $m$ is ....... $kg$.
A car is going round a circle of radius $R_1$ with constant speed. Another car is going round a circle of radius $R_2$ with constant speed. If both of them take same time to complete the circles, the ratio of their angular speeds and linear speeds will be .........