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 $km-s^{-1}$. The wavelength of sound in the tissue is close to

[CBSE PMT 1995]

• A. m
• B. m
• C. m
• D. m

Answer 1

The correct option is A

m

$V=\nu \lambda \lambda =\frac{V}{\nu }=\frac{1.7\times {10}^3}{4.2\times {10}^6}=\frac{17}{42}\times {10}^{-3}=0.4mm=4\times {10}^{-4}m$