Download App

Waves and Sound — JEE physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceJEE physicsWaves and Sound1 Mark
MCQ
The phase difference between two points separated by $\mathrm{Im}$ in a wave of frequency $120 \mathrm{~Hz}$ is $90^{\circ}$. The wave velocity is
  • A
    $180 \mathrm{~m} / \mathrm{s}$
  • B
    $240 \mathrm{~m} / \mathrm{s}$
  • ✓
    $480 \mathrm{~m} / \mathrm{s}$
  • D
    $720 \mathrm{~m} / \mathrm{s}$
✓

Answer

Correct option: C.
$480 \mathrm{~m} / \mathrm{s}$
Path difference $\Delta=\frac{\lambda}{2 \pi} \times \phi \Rightarrow 1=\frac{\lambda}{2 \pi} \times \frac{\pi}{2}$
$ \Rightarrow \lambda=4 m$ Hence $v=n \lambda=120 \times 4=480\mathrm{~m} / \mathrm{s}$

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 "MCQ" from Waves and Sound→Waves and Sound — all question types→JEE physics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

The amount of work done in blowing a soap bubble such that its diameter increases from $d$ to $D$ is ( $T$ = surface tension of the solution)
→
A thick plane mirror shows a number of images of the filament of an electric bulb. Of these, the brightest image is the
→
Two waves have their amplitudes in the ratio $1: 9$. The maximum and minimum intensities when they interfere are in the ratio
→
For a concave mirror, if virtual image is formed, the graph between $m$ and $u$ is of the form
→
A body of mass $5 \mathrm{~kg}$ explodes at rest into three fragments with masses in the ratio $1: 1: 3$. The fragments with equal masses fly in mutually perpendicular directions with speeds of $21 \mathrm{~m} / \mathrm{s}$. The velocity of the heaviest fragment will be
→
A galvanometer is used in laboratory for the null point in electrical experiments. If, on passing a current of $6 \,m A$ it produces a deflection of $2^{\circ},$ its figure of merit is close to :
→
Which of the accompanying $P V$, diagrams best represents an isothermal process
→
A bar magnet of magnetic moment $10 \% /  T$ is free to rotate in a horizontal plane. The work done in rotating the magnet slowly from a direction parallel to a horizontal magnetic field of $4 \times 10 \quad T$ to a direction $60^{\circ}$ from the field will be
→
According to photon theory of light which of the following physical quantities associated with a photon do not/does not change as it collides with an electron in vacuum
→
An ideal transformer has $500$ and $5000$ turn in primary and secondary windings respectively. If the primary voltage is connected to a $6 \mathrm{~V}$ battery then the secondary voltage is
→