Question

The temperature of a furnace is ${2324}^{o}C$ and the intensity is maximum in its radiation spectrum nearly at $1200$ $\mathring{A}$. If the intensity of spectrum in a star is maximum nearly at $4800$ $\mathring{A}$. Find the surface temperature of the star.

• A. ${6219.5}^{0}C$
• B. 649.25 K
• C. 2597 K
• D. ${2597}^{0}C$

Answer 1

The correct option is B 649.25 K

By Wien's displacement Law:
${\lambda }_{m}T=constant$
$\therefore {\lambda }_{m_1}{T}_1={\lambda }_{m_2}{T}_2$
$\therefore T_2=\frac{{\lambda }_{m_1}}{{\lambda }_{m_2}}{T}_1=\frac{1200}{4800}\times (2324+273)$ since T is in absolute scale
$\therefore T_2=\frac{1}{4}\times 2597=649.25K$