The adjoining diagram shows the spectral energy density distribution ${E_\lambda }$of a black body at two different temperatures. If the areas under the curves are in the ratio $16 : 1$ , the value of temperature $T$ is ........ $K$
Medium
Download our app for free and get started
(d) $\frac{{{A_T}}}{{{A_{2000}}}} = \frac{{16}}{1}$ (given)
Area under ${e_\lambda } - \lambda $ curve represents the emissive power of body and emissive power $ \propto {T^4}$
(Hence area under ${e_\lambda } - \lambda $ curve) $ \propto {T^4}$
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
Two bodies $A$and $B$ have thermal emissivities of $0.01$ and $0.81$ respectively. The outer surface areas of the two bodies are the same. The two bodies emit total radiant power at the same rate. The wavelength ${\lambda _B}$ corresponding to maximum spectral radiancy in the radiation from $B$ is shifted from the wavelength corresponding to maximum spectral radiancy in the radiation from $A$, by $1.00\mu m$. If the temperature of $A$ is $5802\;K$
The total radiative power emitted by spherical black body with radius $R$ and temperature $T$ is $P$. If the radius is doubled and the temperature is halved, then the radiative power will be
The energy emitted per second by a black body at ${27^o}C$ is $10\;J$. If the temperature of the black body is increased to ${327^o}C$, the energy emitted per second will be ......... $J$
One end of a thermally insulated rod is kept at a temperature $T_1$ and the other at $T_2$ . The rod is composed of two sections of length $l_1$ and $l_2$ and thermal conductivities $K_1$ and $K_2$ respectively. The temperature at the interface of the two section is
A cane is taken out from a refrigerator at $0°C$ . The atmospheric temperature is $25°C$ . If $t_1$ is the time taken to heat from $0°C$ to $5°C$ and $t_2$ is the time taken from $10°C$ to $15°C$, then
Two identical square rods of metal are welded end to end as shown in figure $(a)$. Assume that $10\, cal$ of heat flows through the rods in $2\, min$. Now the rods are welded as shown in figure, $(b)$. The time it would take for $10$ cal to flow through the rods now, is ........ $\min$
A solid copper cube of edges $1\;cm$ is suspended in an evacuated enclosure. Its temperature is found to fall from ${100^o}C$ to ${99^o}C$ in $100\;s$. Another solid copper cube of edges $2\;cm$, with similar surface nature, is suspended in a similar manner. The time required for this cube to cool from ${100^o}C$ to ${99^o}C$ will be approximately ...... $\sec$