Radiation Shielding MCQ Quiz in मल्याळम - Objective Question with Answer for Radiation Shielding - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക
Last updated on Apr 6, 2025
Latest Radiation Shielding MCQ Objective Questions
Top Radiation Shielding MCQ Objective Questions
Radiation Shielding Question 1:
Two infinitely large parallel plates (I and II) are held at temperatures TI and TII (TI > TII) respectively and placed at a distance 2d apart in a vacuum. An infinitely large flat radiation shield (III) is placed in parallel in between I and II. The emissivities of all the plates are equal. The ratio of the steady-state radiative heat fluxes with and without the shield is:
Answer (Detailed Solution Below)
Radiation Shielding Question 1 Detailed Solution
In case if there are n screens used, all of them are having the same emissivity as those of plate.
\({q_{withscreen}} = \left( {\frac{1}{{n + 1}}} \right){q_{withoutscreen}}\)
Here, n = 1
\(\therefore {q_{withscreen}} = \left( {\frac{1}{{1 + 1}}} \right){q_{withoutscreen}}\)
\(\therefore \frac{{{q_{with}}}}{{{q_{without}}}} = \frac{1}{2} = 0.5\)Radiation Shielding Question 2:
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 this radiant heat transfer by inserting thin parallel shields of same emissivity on both sides. The number of shields should be
Answer (Detailed Solution Below)
Radiation Shielding Question 2 Detailed Solution
Let N be the required number of shields. When emissivities of the main radiating surface and those of parallel radiation shields are equal, then
\(\frac{{With\;shields}}{{without\;shields}} = \frac{1}{{N + 1}}\)
Given, \({Q_{shielded}} = \left( {1 - 0.75} \right){Q_{un - shieled}}\)
\(\therefore \frac{1}{{\left( {N + 1} \right)}} = 0.25\)
Or N = 3