Question

The wavelength range of thermal radiation is

• A. from $4000\mathring{A}$ to $7000\mathring{A}$
• B. from $7700\mathring{A}$ to $4\times {10}^6\mathring{A}$
• C. from ${10}^6\mathring{A}$ to ${10}^8\mathring{A}$
• D. from $4\times {10}^{-12}\mathring{A}$ to $4\times {10}^8\mathring{A}$

Answer 1

Answer: (B)

from $7700\mathring{A}$ to $4\times {10}^6\mathring{A}$

The wavelength range of thermal radiation is from $7700\mathring{A}$ to $4\times {10}^6\mathring{A}$. Thermal radiation is the emission of electromagnetic waves from all matter that has a temperature greater than absolute zero. It represents a conversion of thermal energy into electromagnetic energy. Thermal energy consists of the kinetic energy of random movements of atoms and molecules in matter.