A black body at  $227^{o}C$ radiates heat at the rate of 7 $cals/c{m}^{2}s$ . At a temperature of $727^{o}C$ , the rate of heat radiated in the same units will be

Correct Option - 2


Detailed Solution:

Rate of heat radiated at (227 + 273) K

$=7cals/\left(c{m}^{2}s\right)$

Let rate of heat radiated at (727+ 273)  K = xcals/ (cm²s)

By Stefan's law 

 

<p>Rate of heat radiated at (227 +&lt;!- [if gte mso 9]>&lt;xml&gt; <o:OLEObject Type="Embed" ProgID="Equation.DSMT4" ShapeID="_x0000_i1025" DrawAspect="Content" ObjectID="_1819714741"> </o:OLEObject>&lt;/xml&gt;&lt;! [endif]-&gt;273) K<br>&lt;!- [if gte mso 9]>&lt;xml&gt; <o:OLEObject Type="Embed" ProgID="Equation.DSMT4" ShapeID="_x0000_i1026" DrawAspect="Content" ObjectID="_1819714742"> </o:OLEObject>&lt;/xml&gt;&lt;! [endif]-&gt;</p><p><span class="mathml" contenteditable="false"> <math> <mrow> <mo>=</mo> <mn>7</mn> <mi>c</mi> <mi>a</mi> <mi>l</mi> <mi>s</mi> <mo>/</mo> <mrow> <mo> (</mo> <mrow> <mi>c</mi> <msup> <mrow> <mi>m</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msup> <mi>s</mi> </mrow> <mo>)</mo> </mrow> </mrow> </math> </span></p><p>Let rate of heat radiated at (727+ 273)&nbsp; K = xcals/ (cm²s)</p><p>By Stefan's law&nbsp;</p><div class="photo-widget-full"><div class="figure"><picture><source srcset="" media=" (max-width: 500px)"><img src="https://images.shiksha.com/mediadata/images/1758189274phpITaXUM.jpeg" alt="" width="249" height="70" loading="lazy"></picture></div></div><p>&nbsp;</p>

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