MCQ
At $127^o C$ radiates energy is $2.7 \times 10^{-3} J/s$. At ....... $K$ temperature radiated energy is $4.32 \times 10^6 J/s$
  • A
    $400$
  • B
    $4000$
  • $80000 $
  • D
    $40000$

Answer

Correct option: C.
$80000 $
c
(c) Energy radiated from a body $Q = A\varepsilon \sigma {T^4}t$

==> $\frac{{{Q_2}}}{{{Q_1}}} = {\left( {\frac{{{T_2}}}{{{T_1}}}} \right)^4}$ ==> $\frac{{{T_2}}}{{{T_1}}} = {\left( {\frac{{{Q_2}}}{{{Q_1}}}} \right)^{1/4}} = {\left( {\frac{{4.32 \times {{10}^6}}}{{2.7 \times {{10}^{ - 3}}}}} \right)^{1/4}}$

$ = {\left( {\frac{{16 \times 27}}{{27}} \times {{10}^8}} \right)^{1/4}}$$ = 2 \times {10^2}$

==>${T_2} = 200 \times {T_1} = 80000\,K$

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