Q104 / 150 · MHT CET 2012 · Physics
The frequency of radio waves corresponding to a wavelength of $10 \mathrm{~m}$ is
- Correct answerA$3 \times 10^{7} \mathrm{~Hz}$
- B$3.3 \times 10^{8} \mathrm{~Hz}$
- C$3 \times 10^{9} \mathrm{~Hz}$
- D$3 \times 10^{-7} \mathrm{~Hz}$
Solution
Wavelength, $\lambda=10 \mathrm{~m}$
$$
c=3 \times 10^{8} \mathrm{~ms}^{-1}
$$
By using $c=v \lambda$
$$
v=\frac{c}{\lambda}=\frac{3 \times 10^{8}}{10}=3 \times 10^{7} \mathrm{~Hz}
$$
Hence, the correct answer is option: 'A'.