$f^{\prime}=\frac{v}{v-v_s} f_0$
$f$ is such that $f=\frac{110}{100} f_0$
When $\frac{v}{v-v_s}=\frac{110}{100}$
$100 v=110 v-110 v_s$
$v=11 v_s$
When source is received
$\frac{v}{v+v_s} f_0=\frac{x}{100} f_0$
Putting $v=11 v_s$
$\frac{11}{12} \times 100=x$
$x=91.66 \%$
$\%$ change $=100-91.66=8.5 \%$
${z_1},{z_2}$ and ${z_3}$ as${z_1} = A\sin (kx - \omega \,t)$, ${z_2} = A\sin (kx + \omega \,t)$ and ${z_3} = A\sin (ky - \omega \,t)$.
Which of the following represents a standing wave
(image)
[$A$] The time $\mathrm{T}_{A 0}=\mathrm{T}_{\mathrm{OA}}$
[$B$] The velocities of the two pulses (Pulse $1$ and Pulse $2$) are the same at the midpoint of rope.
[$C$] The wavelength of Pulse $1$ becomes longer when it reaches point $A$.
[$D$] The velocity of any pulse along the rope is independent of its frequency and wavelength.
$(A)$ The number of nodes is $5$ .
$(B)$ The length of the string is $0.25 \ m$.
$(C)$ The maximum displacement of the midpoint of the string its equilibrium position is $0.01 \ m$.
$(D)$ The fundamental frequency is $100 \ Hz$.