Question

A microwave and an ultrasonic sound wave have the same wavelength. Their frequencies are in the ratio (approximately)

• A. ${10}^2$
• B. ${10}^4$
• C. ${10}^6$
• D. ${10}^8$

Answer 1

Answer: (C)

${10}^6$

Frequency of microwaves, ${\upsilon }_m\approx {10}^{11}Hz$
Frequency of ultrasonic sound waves,${\upsilon }_m\approx {10}^{5}Hz$
$\therefore \frac{{\upsilon }_m}{{\upsilon }_u}=\frac{{10}^{11}}{{10}^5}={10}^6$