MCQs
Total Questions : 448
| Page 32 of 45 pages
Answer: Option D. -> RN = ρ V l /μ
Question 312. Two long parallel surfaces each of emissivity 0.7 are maintained at different temperatures and accordingly have radiation heat exchange between them. It is desired to reduce 75% of the radiant heat transfer by inserting thin parallel shields of emissivity 1 on both sides. The number of shields should be
Answer: Option B. -> Three
Answer: Option A. -> 1/h₁ + 1/h₂ + 1/h₃
Answer: Option D. -> Hot body to cold body
Answer: Option C. -> A vapour seal
Answer: Option B. -> None of these
Answer: Option A. -> Biot number
Answer: Option A. -> One dimensional cases only
Answer: Option C. -> Free convection
Answer: Option A. -> Emissive power