Answer: 6.67 × 10⁻⁹ N.
- A 6.67 × 10⁻⁹ N
- B 6.67 × 10⁻⁶ N
- C 3.33 × 10⁻⁹ N
- D 1 × 10⁻³ N
Correct answer: A. 6.67 × 10⁻⁹ N
Explanation: Radiation pressure on mirror = 2I/c. I = P/A = 10⁻³/10⁻⁶ = 10³ W/m². Pressure = 2×10³/(3×10⁸) = 6.67×10⁻⁶ Pa. Force = P×A = 6.67×10⁻⁶ × 10⁻⁶ = 6.67×10⁻¹² N.
In an electromagnetic wave, the oscillating electric field (E) and magnetic field (B) are perpendicular to each other and to the direction the wave travels - a purely transverse wave that needs no medium, unlike sound.
Concept context
Maxwell's equations, EM spectrum, properties, and applications of each band.