Question

The temperature of a furnace is $2324$${}^o$C and the intensity is maximum in its spectrum nearly at $12000A$${}^o$. If the intensity in the spectrum of star is maximum nearly at $4800A$${}^o$, then the surface temperature of the star is :

• A. 8400${}^o$C
• B. 6219${}^o$C
• C. 7200${}^o$C
• D. 5900${}^o$C

Answer 1

Answer: (B)

6219${}^o$C

According to wein's displacement law, ${\lambda }_{max}$ is inversely proportional to temperature in kelvin g

$\frac{{\lambda }_1}{{\lambda }_2}=\frac{T_2}{T_1}$

$\Rightarrow \frac{12000}{4800}=\frac{T_2}{(2324+273)}\Rightarrow T_2=6492.5K$

So, in ℃, $T_2=6492.5-273=6219.5℃$

$T_2\approx 6219℃$