Question:-
Consider the following statements:
1. For metals, the value of absorptivity is high.
2. For nonconducting materials, reflectivity is low
3. For polished surfaces, reflectivity is high
4. For gases, reflectivity is very low
Of these statements
Option (A)
2, 3 and 4 are correct
Option (B)
3 and 4 are correct
Option(C)
1, 2 and 4 are correct
Option(D)
1 and 4 are correct
Correct Option:
(C)
Question Solution:
The emissivity of metallic surface is generally small. 0.02 for highly polished gold and silver.(Therefore absorptivity will be high). Emissivity of nonconducting material is high so reflectivity low
For gases, radiation is not a surface phenomenon but volumetric phenomena
question-answer-faq-6053