Download App

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

Gujarat BoardEnglish MediumSTD 11 SciencePhysics14. waves and sound1 Mark
MCQ
A hospital uses an ultrasonic scanner to locate tumours in a tissue. The operating frequency of the scanner is $4.2 MHz$. The speed of sound in a tissue is $1.7 \,km-s^{-1}$. The wavelength of sound in the tissue is close to
  • ✓
    $4 \times {10^{ - 4}}\,m$
  • B
    $8 \times {10^{ - 3}}\,m$
  • C
    $4 \times {10^{ - 3}}\,m$
  • D
    $8 \times {10^{ - 4}}\,m$
✓

Answer

Correct option: A.
$4 \times {10^{ - 4}}\,m$
a
(a) $\lambda = \frac{v}{n} = \frac{{1.7 \times 1000}}{{4.2 \times {{10}^6}}} = 4 \times {10^{ - 4}}\,m$

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

Similar questions

Diffusion current in a p-n junction is greater than the drift current in magnitude:
→
The force required to separate two glass plates of $10^{-2}m^2$ with a film of water $0.05\ mm$ thick between them, is $($surface tension of water is $70 \times 10^{-3} \mathrm{Nm}^{-1}):$
→
In the solar system, which is conserved
→
Which two of the given transverse waves will give stationary waves when get superimposed

${z_1} = a\cos (kx - \omega \,t)$.....$(A)$

${z_2} = a\cos (kx + \omega \,t)$.....$(B)$

${z_3} = a\cos (ky - \omega \,t)$..... $(C)$

→
The adjoining diagram shows three soap bubbles $A, B$ and $C$ prepared by blowing the capillary tube fitted with stop cocks, $S_1$, $S_2$ and $S_3$. With stop cock $S$ closed and stop cocks $S_1$, $S_2$ and $S_3$ opened
→
When a capillary tube is dipped in water it rises upto $8$ $cm$ in the tube. What happens when the tube is pushed down such that its end is only $5$ $cm$ above the outside water level
→
A body of mass $0.5\ kg$ travels in a straight line with velocity $v = a x^{3/2}$ where ${a}=5 {~m}^{-1 / 2}{~s}^{-1}$. The work done by the net force during its displacement from $x = 0$ to $x = 2m$ is:
→
If $R$ and $H$ are the horizontal range and maximum height attained by a projectile, than its speed of projection is ..........
→
An ideal gas follows a process $PT =$ constant. The correct graph between pressure $\&$ volume is
→
An air column in a pipe, which is closed at one end, will be in resonance wtih a vibrating tuning fork of frequency $264\, Hz$ if the length of the column in $cm$ is (velocity of sound $= 330\, m/s$)
→