A string is stretched between fixed points separated by 75.0 cm. … - Vidyadip

MCQ

A string is stretched between fixed points separated by $75.0\ cm$. It is observed to have resonant frequencies of $420\ Hz$ and $315\ Hz.$ There are no other resonant frequencies between these two. Then, the lowest resonant frequency for this string is .... $Hz$

A
$10.5$
✓
$105$
C
$1.05$
D
$1050$

✓

Answer

Correct option: B.

$105$

b
Given $\frac{\mathrm{nv}}{2 \ell}=315$ and $(\mathrm{n}+1) \frac{\mathrm{v}}{2 \ell}=420$

$\Rightarrow \frac{n+1}{n}=\frac{420}{315} \Rightarrow n=3$

Hence $3 \times \frac{v}{2 \ell}=315 \Rightarrow \frac{v}{2 \ell}=105 \mathrm{Hz}$

Lowest resonant frequency is when $n=1$

Therefore lowest resonant frequency $=105 \mathrm{Hz}$

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

Find moment of inertia of a uniform annular disc of mass $100 \,g$, having inner radius $10\, cm$ and outer radius $20\, cm$, about an axis passing through its centre and perpendicular to its plane.

Oxygen is $16$ times heavier than hydrogen. Equal volumes of hydrogen and oxygen are mixed. The ratio of speed of sound in the mixture to that in hydrogen is

A projectile is thrown upward with a velocity $v_0$ at an angle $\alpha$ to the horizontal. The change in velocity of the projectile when it strikes the same horizontal plane is

In case of a simple pendulum, time period versus length is depicted by

Calculate the acceleration (In $m/s^{2}$) of the block and trolly system shown in the figure. The coefficient of kinetic friction between the trolly and the surface is $0.05 .\left( g =10\; m / s ^{2},\right.$ mass of the string is negligible and no other friction exists).

A block $P$ of mass $m$ is placed on a smooth horizontal surface. A block $Q$ of same mass is placed over the block $P$ and the coefficient of static friction between them is ${\mu _S}$. A spring of spring constant $K$ is attached to block $Q$. The blocks are displaced together to a distance $A$ and released. The upper block oscillates without slipping over the lower block. The maximum frictional force between the block is

A vessel containing $5\, litres$ of a gas at $0.8 \,pa$ pressure is connected to an evacuated vessel of volume $3$ litres. The resultant pressure inside will be ...... $pa$ (assuming whole system to be isolated)

The $x-t$ graph of a particle moving along a straight line is shown in figure The speed-time graph of the particle is correctly shown by

A train is moving towards north. At one place it turns towards north-east, here we observe that

The equation of motion of a projectile is $y=12 x-\frac{3}{4} x^2$ $..........\,m$ is the range of the projectile.