Download App

14. waves and sound — Physics STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 SciencePhysics14. waves and sound1 Mark
MCQ
A tuning fork of frequency $280\,\, Hz$ produces $10$ beats per sec when sounded with a vibrating sonometer string. When the tension in the string increases slightly, it produces $11$ beats per sec. The original frequency of the vibrating sonometer string is ... $Hz$
  • A
    $269$
  • B
    $291$
  • C
    $270 $
  • ✓
    $290$
✓

Answer

Correct option: D.
$290$
d
The frequency of tuning fork is $\nu_{T}=280 \mathrm{Hz}$

The frequency of sonometer string is $\nu_{s}$

The frequency of beats is

$\left|\nu_{T}-\nu_{s}\right|=10$

Hence, the frequency of sonometer string is either $10 \mathrm{Hz}$ more i.e. $290 \mathrm{Hz}$ or $10 \mathrm{Hz}$ lessi.e. $270 \mathrm{Hz}$ because increase in this frequency will reduce the frequency of beats.

But when tension is applied to the string its frequency increases and number of beats also increases. Hence, frequency of string cannot be $290 \mathrm{Hz}$.

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

Explore more

More "M.C.Q (1 Marks)" from 14. waves and sound→14. waves and sound — all question types→Physics STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

Why the spring is made up of steel in comparison of copper
→
An ideal gas is expanding such that $\mathrm{PT}^2=$ constant. The coefficient of volume expansion of the gas is
→
Consider the following two statements:
$A.$ The linear momentum of a particle is independent of the frame of reference.
$B.$ The kinetic energy of a particle is independent of the frame of reference.
→
The radius of the earth is $6400\, km$ and $g = 10\,m/{\sec ^2}$. In order that a body of $5 \,kg$ weighs zero at the equator, the angular speed of the earth is
→
A solid cone is placed on a horizontal surface has height $h$, radius $R$ and apex angle $\theta$ as show.If gravitational potential energy of the cone does not change as position of the cone is changed from figure $(A)$ to figure $(B)$, then,
→
In Melde's experiment, the string vibrates in $4$ loops when a $50 \,gram$ weight is placed in the pan of weight $15\, gram.$ To make the string to vibrates in $6$ loops the weight that has to be removed from the pan is
→
If the change in the value of $‘g’$ at a height $h$ above the surface of the earth is the same as at a depth $x$ below it, then (both $x$ and $h$ being much smaller than the radius of the earth)
→
A bullet is fired from a gun. The force on the bullet is given by:

$F =  600 - 2 \times 10^5\ t$

Where $F$ is in newton and $t$ in second. The force on the bullet becomes zero as soon as it leaves the barrel. What is the average impulse imparted to the bullet?

→
A thermodynamic system is taken from an original state $D$ to an intermediate state $E$ by the linear process shown in the figure. Its volume is then reduced to the original volume from $E$ to $F$ by an isobaric process. The total work done by the gas from $D$ to $E$ to $F$ will be $......J$
→
A stone is shot straight upward with a speed of $20\, m/sec$ from a tower $200\, m$ high. The speed with which it strikes the ground is approximately........$m/sec$
→