The speed of electromagnetic waves in air is
A. 3 × 105 km/s
B. 3 × 106 km/s
C. 3 × 107 km/s
D. 3 × 108 km/s
Answer:A
The speed of electromagnetic waves in air is
A. 3 × 105 km/s B. 3 × 106 km/s C. 3 × 107 km/s D. 3 × 108 km/s