Q. A hospital uses an ultrasonic scanner to locate tumours in a tissue. The operating frequency of the scanner is $4.0\ MHz.$ The speed of should in a tissue is $1.7\ km - s^{- 1}.$ The wavelength of sound in the tissue is close to
A) $4 \times 10^{- 4}m$
B) $8 \times 10^{- 3}m$
C) $4 \times 10^{- 3}m$
D) $8 \times 10^{- 4}m$
Explanation
(a) $\lambda = \frac{v}{n} = \frac{1.7 \times 1000}{4.2 \times 10^{6}} = 4 \times 10^{- 4}m$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.