Question 25
WavesThe diagram above represents a transverse electromagnetic wave travelling with speed 3.0 × 108 m s−1. What is the frequency of the wave?
- A.3.0 × 107 Hz
- B.9.0 × 107 Hz
- C.1.0 × 109 Hz
- D.3.0 × 109 Hz
Show the answer and explanation
Answer: D (3.0 × 109 Hz)
Explanation
Three complete waves fit in 0.3 m, so λ = 0.1 m. f = v/λ = 3.0 × 108/0.1 = 3.0 × 109 Hz.