Question

Incorrect Answers: AE, AEH, CEH

Assume that the walls in your room are painted white. Which of the following statements are correct? Choose all that apply

A. The white walls in your room reflect visible light but they do not emit visible light.

B. The white walls in your room emit visible light but they do not reflect visible light.

C. The white walls in your room reflect and emit visible light.

D. The white walls in your room absorb and emit infrared radiation.

E. The white walls in your room absorb infrared radiation but do not emit infrared radiation.

F. The white walls in your room emit infrared radiation but do not absorb infrared radiation.

G. The white walls in your room absorb infrared radiation and visible light.

H. The white walls in your room absorb infrared radiation but do not absorb visible light.

I. The white walls in your room absorb visible light but do not absorb infrared radiation.

Answer 1

The reflectivity, absorptivity and emissitivity are the material property which depends on the frequency of incoming electromagnetic waves. A white color is good reflective surface for visible spectrum of electromagnetic waves whereas it is bad for infrared.

So, The white wall will reflect visible light and absorb infrared radiation. When an object absorbs energy it will radiate it in the form of heat so thw white wall will also radiate infrared radiation.

So,option A, The white walls in your room reflect visible light but they do not emit visible light

option D, The white walls in your room absorb and emit infrared radiation

option H, The white walls in your room absorb infrared radiation but do not absorb visible light