Download App

Sound — Physics STD 11 Science — Question

Maharashtra BoardEnglish MediumSTD 11 SciencePhysicsSound1 Mark
MCQ
When the observer moves towards the stationary source with velocity, $V_1$, the apparent frequency of emitted note is $F_1$. When the observer moves away from the source with velocity $V_1$, the apparent frequency is $F_2$. If $V$ is the velocity of sound in air and $\frac{F_1}{F_2}=2$ then $\frac{V}{V_1}=$ ?
  • A
    2
  • ✓
    3
  • C
    4
  • D
    5
✓

Answer

Correct option: B.
3
(b) :When the observer moves towards the stationary source, apparent frequency of emitted note,
$
F_1=\left(\frac{V+V_1}{V}\right) n ...(i)
$
When the observer moves away from the stationary source, apparent frequency of emitted note
$
F_2=\left(\frac{V-V_1}{V}\right) n
$ ...(ii)
Dividing eqn. (i) by eqn. (ii), we get
$
\begin{aligned}
& \frac{F_1}{F_2}=\frac{V+V_1}{V-V_1} \\
& \because \quad \frac{F_1}{F_2}=2 \text { (given) } \therefore \quad \frac{V+V_1}{V-V_1}=2 \\
& \Rightarrow \quad V+V_1=2 V-2 V_1 \Rightarrow V=3 V_1 \text { or } \frac{V}{V_1}=3
\end{aligned}
$

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 Sound→Sound — all question types→Physics STD 11 Science question papers→Maharashtra Board STD 11 Science question papers→Maharashtra Board question paper generator→

Similar questions

A particle is describing the circular path of radius 20 m in every 2 s. The average angular speed of the particle during 4 s is
→
If $\omega_E$ and \[\omega_H\] are the angular velocities of the earth rotating about its own axis and the hour hand of the clock respectively, then
→
A force of 6 N acts on a body of mass 1 kg initially at rest and during this time, the body attains a velocity of 30 m/s. The time for which the force acts on a body is
→
A body is projected with a vertical velocity of 30 m/s at an angle of $30^{\circ}$ with the horizontal, the maximum height and horizontal range are respectively
→
The gravitational force between two bodies is ______
→
The linear velocity of a particle on the N-pole of the earth is
→
The ratio of magnetic induction along the axis to magnetic induction along the equator of a magnet is
→
An electron of mass ' $m$ ' and charge ' $q$ ' is accelerated from rest in a uniform electric field of strength ${ }^4 E$. The velocity acquired by it as it travels a distance $l$ is
→
Particle of masses m, 2m, 3m,...., nm grams are placed on the same line at distance $l, 2 l$,$3 l$, ....... $n l$ cm from a fixed point. The distance of centre of mass of the particles from the fixed point in centimetres is
→
Displacement time graph cannot be
→