Wave Mechanics Question 640
Question: 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. The wavelength of sound in tissue is close to
Options:
A) $ 4\times {{10}^{-4}}m $
B) $ 8\times {{10}^{-4}}m $
C) $ 4\times {{10}^{-3}}m $
D) $ 8\times {{10}^{-3}}m $
Show Answer
Answer:
Correct Answer: A
Solution:
[a] Frequency $ (n)=4.2MHz=4.2\times 10^{6}Hz $ and speed of sound (v) $ =1.7km/s=1.7\times 10^{3}m/s $ . Wave length of sound in tissue $ (\lambda )=\frac{v}{n}=\frac{1.7\times 10^{3}}{4.2\times 10^{6}}=4\times {{10}^{-4}}m. $
BETA
