A string under a tension of 129.6 , , N produces 10 , , beats /se… - Vidyadip

MCQ

A string under a tension of $129.6\,\, N$ produces $10\,\, beats /sec$ when it is vibrated along with a tuning fork. When the tension is the string is increased to $160\,\, N,$ it sounds in unison with same tuning fork. calculate fundamental freq. of tuning fork .... $Hz$

✓
$100$
B
$50$
C
$150$
D
$200$

✓

Answer

Correct option: A.

$100$

a
frequency of tuning fork $ = \frac{{\sqrt {\frac{{160}}{{\rm{m}}}} }}{{2l}}$

According to the question

$\frac{1}{{2l}}\sqrt {\frac{{160}}{{\rm{m}}}} - \frac{1}{{2l}}\sqrt {\frac{{129.6}}{{\rm{m}}}} = 10$

$\frac{1}{{2l}}\sqrt {\frac{{10}}{m}} [4 - 3.6] = 10 \Rightarrow \frac{1}{{2l}}\sqrt {\frac{{10}}{m}} = 25$

so ${{\rm{V}}_{{\rm{TF}}}} = \frac{1}{{2l}}\sqrt {\frac{{160}}{{\rm{m}}}} = 4\left[ {\frac{1}{{2l}}\sqrt {\frac{{10}}{{\rm{m}}}} } \right] = 100\,{\rm{Hz}}$

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

A force of $(3\,\hat i + 4\,\hat j)$ Newton acts on a body and displaces it by $(3\,\hat i + 4\hat j)\,m.$ The work done by the force is .............. $\mathrm{J}$

Amount of solar energy received on the earth's surface per unit area per unit time is defined a solar constant. Dimension of solar constant is

A composite rod made of three rods of equal length and cross-section as shown in the fig. The thermal conductivities of the materials of the rods are $K/2, 5K$ and $K$ respectively. The end $A$ and end $B$ are at constant temperatures. All heat entering the face Agoes out of the end $B$ there being no loss of heat from the sides of the bar. The effective thermal conductivity of the bar is

A wheel is rotating at $900\ r.p.m.$ about its axis. When the power is cut-off, it comes to rest in $1 \,minute.$ The angular retardation in $radian$/$s^2$ is

A cube of aluminum of side $0.1m$ is subjected to a shearing force of $100N.$ The top face of the cube is displaced through $0.02\ cm$ with respect to the bottom face. The shearing strain would be:

The angle between $\vec{\text{A}}=\hat{\text{i}}+\hat{\text{j}}$ and $\vec{\text{B}}=\hat{\text{i}}-\hat{\text{j}}$ is

A dancer moves counterclockwise at constant speed around the path shown below. The path is such that the lengths of its segments, $PQ, QR, RS$, and $SP$, are equal. Arcs $QR$ and $SP$ are semicircles. Which of the following best represents the magnitude of the dancer’s acceleration as a function of time $t$ during one trip around the path, beginning at point $P$ ?

A uniform rod of mass $15\,kg$ and length $5\,m$ is held stationary with the help of a light string as shown. Then tension in the string is ......... $N.$

Two particles are at rest on a straight track and they are separated from each other by $100\, m$. They start their motion in the same direction, with the same acceleration $10\, m/s^{-2}$. Their relative displacement after $10\, s$ will be

A uniform metal plate shaped like a triangle $A B C$ has a mass of $540 \,g$. The length of the sides $A B, B C$ and $C A$ are $3 \,cm , 5 \,cm$ and $4 \,cm$, respectively. The plate is pivoted freely about the point $A$. What mass must be added to a vertex, so that the plate can hang with the long edge horizontal?