Download App

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

Rajasthan BoardEnglish MediumSTD 11 SciencePhysics14. waves and sound1 Mark
MCQ
A second harmonic has to be generated in a string of length $l$ stretched between two rigid supports. The point where the string has to be plucked and touched are
  • ✓
    Plucked at $\frac{l}{4}$ and touch at $\frac{l}{2}$
  • B
    Plucked at $\frac{l}{4}$ and touch at $\frac{{3l}}{4}$
  • C
    Plucked at $\frac{l}{2}$ and touched at $\frac{l}{4}$
  • D
    Plucked at $\frac{l}{2}$ and touched at $\frac{{3l}}{4}$
✓

Answer

Correct option: A.
Plucked at $\frac{l}{4}$ and touch at $\frac{l}{2}$
a
(a) Second harmonic means $2$ loops in a total length
Hence plucking distance from one end $ = \frac{l}{{2p}} = \frac{l}{{2 \times 2}} = \frac{l}{4}.$

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→Rajasthan Board STD 11 Science question papers→Rajasthan Board question paper generator→

Similar questions

A rolling wheel of $12 \,kg$ is on an inclined plane at position $P$ and connected to a mass of $3 \,kg$ through a string of fixed length and pulley as shown in figure. Consider $PR$ as friction free surface. The velocity of centre of mass of the wheel when it reaches at the bottom $Q$ of the inclined plane $P Q$ will be $\frac{1}{2} \sqrt{ xgh } \,m / s$. The value of $x$ is.............
→
An object of mass $5\, kg$ is attached to the hook of a spring balance and the balance is suspended vertically from the roof of a lift. The reading of the spring balance when the lift is going up with an acceleration of $0.25\, ms^{-2}$ is  ......... $N$ $(g = 10\, m/s^2)$
→
The point through which the total weight of an object appears to act for any orientation of the object is ______.
→
If a vector $\vec A$ is parallel to another vector $\vec B$ then the resultant of the vector $\vec A \times \vec B$ will be equal to
→
The moment of inertia of a body about a given axis is $2.4\ kg-m^2$.  To produce a rotational kinetic energy of $750\ J$, an angular acceleration of $5\ rad/s^2$ must be applied about that axis for.......... $\sec$
→
The figure given below shows the variation in the internal energy $U$ with volume $V$ of $2.0\ mole$ of an ideal gas in a cyclic process $abcda$ . The temperatures of the gas during the processes $ab$ and $cd$ are $500\ K$ and $300\ K$ respectively, the heat absorbed by the gas during the complete process is  .... $J$

(Take $R$ = $8.3\ J/mol-K$ and $ln\ 2$ = $0.69$)

→
A spring executes $SHM$ with mass of $10\,kg$ attached to it. The force constant of spring is $10\,N/m$.If at any instant its velocity is $40\,cm/sec$, the displacement will be .... $m$ (where amplitude is $0.5\,m$)
→
A particle of mass $m$ moving horizontally with $v_0$ strikes $a$ smooth wedge of mass $M$, as shown in figure. After collision, the ball starts moving up the inclined face of the wedge and rises to $a$ height $h$. The final velocity of the wedge $v_2$ is

 

→
If three uniform spheres, each having mass M and radius r, are kept in such a way that each touches the other two, the magnitude of the gravitational force on any sphere due to the other two is:
→
A rigid body can be hinged about any point on the $x$ -axis. When it is hinged such that the hinge is at $x$, the moment of inertia is given by $I = 2x^2 - 12x + 27$ The $x$ -coordinate of centre of mass is
→