The area enclosed between $E_{\lambda}-\lambda$ curve and $\lambda-$ axis is equal to

Wien's displacement law fails for

The S.I. units of the constant in Wien's displacement law are

The maximum energy in thermal radiation from a source occurs at the wavelength $4000 \stackrel{0}{\mathrm{A}}$. The effective temperature of the source is

The wavelength of maximum energy released during an atomic explosion was $2.93\times {10}^{-10} \mathrm{m}$. Given that Wien's constant is $2.93\times {10}^{-3} \mathrm{m} \mathrm{K}$, the maximum temperature attained must be of the order of

The wavelength of maximum emitted energy of a body at $700 \mathrm{K}$ is $4.08 \mathrm{\mu m}$. If the temperature of the body is raised to $1400 \mathrm{K}$, the wavelength of maximum emitted energy will be

Two stars emit maximum radiation at wavelengths $3600 \mathrm{\AA }$ and $4800 \mathrm{\AA }$, respectively. The ratio of their temperatures is

A star radiates maximum energy of wavelength ${\lambda }_{\mathrm{m}}$ at temperature $T$. What will be the temperature of another star which radiates maximum energy of wavelength $2{\lambda }_{\mathrm{m}}$?