Thermal Properties of Matter - Result Question 26

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

======= ####27. A black body at $227^{\circ} C$ radiates heat at the rate of $7 cals / cm^{2} s$. At a temperature of $727^{\circ} C$, the rate of heat radiated in the same units will be:

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/thermal-properties-of-matter/thermal-properties-of-matter—result-question-26.md (a) 50

(b) 112

(c) 80

(d) 60

[2009]

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Answer:

Correct Answer: 27. (b)

Solution:

  1. (b) According to Stefan’s law $E=\sigma T^{4}$,

$T_1=500 K$

$T_2=1000 K$

$\frac{E_2}{E_1}=(\frac{T_2}{T_1})^{4}=(\frac{1000}{500})^{4}=16$

$\therefore \quad E_2=16 \times 7=112 cal / cm^{2} s$