Question
A string fixed at both ends vibrates in three loops. The wave length is $10\, cm$ . The length of string is .... $cm$
✓
Answer
In general, the length of string is $L = \frac{{(n - 1)\lambda }}{2}$ $n \to $ Number of loops $= $ Number of harmonics in question $n = 4 \,;\, \lambda = 10\, cm$
$L = (4 - 1) \times \frac{{10}}{2} = 15\,cm$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
The amplitude of $15 \sin (1000 \pi t )$ is modulated by $10 \sin (4 \pi t)$ signal. The amplitude modulated signal contains frequencies of
→$1.$ $500\,Hz$. $2.$ $2\,Hz$ $3.$ $250\,Hz$ $4.$ $498\,Hz$ $5.$ $502\,Hz$
Choose the correct answer from the options given below:
In the figure a capacitor is filled with dielectrics. The resultant capacitance is
The temperature, at which the root mean square velocity of hydrogen molecules equals their escape velocity from the earth is closest to : [Boltzmans Constant $k_B = 1.38\times10^{-23}\, J / K$ Avogadro number $N_A = 6.02\times10^{26}\, / kg$ Radius of Earth $: 6.4\times10^6\, m$ Gravitation acceleration on Earth $= 10\, ms^{-2}$]
→A uniform spherical planet (Radius $R$) has acceleration due to gravity at its surface $g.$ Points $P$ and $Q$ located inside and outside the planet have acceleration due to gravity $\frac{g}{4} .$ Maximum possible separation between $P$ and $Q$ is
→If lateral magnification is $-2$ for virtual object for a spherical mirror then
→When one mole of monatomic gas is mixed with one mole of a diatomic gas, then the equivalent value of $\gamma$ for the mixture will be (vibration mode neglected)
→Two identical photo-cathodes receive light of frequencies ${f_1}$ and ${f_2}$. If the velocities of the photo electrons (of mass $m$) coming out are respectively ${v_1}$ and ${v_2}$, then
→The far point of a myopic person is $80\, cm$ in front of the eye. What is the eye power of the lens required to enable him to see very distant objects clearly?
→Abody performs simple harmonic oscillations along the straight line $ABCDE$ with $C$ as the midpoint of $AE.$ Its kinetic energies at $B$ and $D$ are each one fourth of its maximum value. If $AE = 2R,$ the distance between $B$ and $D$ is
→When light is incident on a medium at angle $i$ and refracted into a second medium at an angale $r,$ the graph of $\sin i$ vs $\sin r$ is as shown in the graph. From this, one can conclude that is as shown in the graph. From this, one can conclude that :-
→$(a)$ Velocity of light in the second medium is $1.73$ times the velocity of light in the $I$ medium
$(b)$ Velocity of light in the $I$ medium is $1.73$ times the velocity in the $II$ medium
$(c)$ The critical angle for the two media is given by $\sin \,{i_c}\, = \,\frac{1}{{\sqrt 3 }}$
$(d)$ $\sin \,{i_c}\, = \,\frac{1}{2}$