Question

Wavelength of the wave with $30$ MHz frequency is

• A. $1$ cm
• B. $10$ cm
• C. $100$ cm
• D. $1000$ cm
• E. $10000$ cm

Hint:

Always convert MHz to Hz before using $\lambda = c/f$.

Answer 1

The Correct Option is D

Concept:
\[ \lambda = \frac{c}{f} \]

Step 1: Substitute values.
\[ c = 3 \times 10^8,\quad f = 30 \times 10^6 \] \[ \lambda = \frac{3 \times 10^8}{30 \times 10^6} = \frac{3}{30} \times 10^2 = 10 \text{ m} \]

Step 2: Convert to cm.
\[ 10 \text{ m} = 1000 \text{ cm} \]