Answer: 500 nm (visible).
- A 500 nm (visible)
- B 10000 nm (IR)
- C 100 nm (UV)
- D 1 mm (microwave)
Correct answer: A. 500 nm (visible)
Explanation: Wien's displacement law: λ_max T = 2.898 × 10⁻³ m·K. For T = 5800 K: λ_max = 2.898×10⁻³/5800 ≈ 500 nm (visible light). Earth at 300 K emits at λ_max ≈ 10 μm (infrared).
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.