Suppose the sun expands so that its radius becomes $100$ times its present radius and its surface temperature becomes half of its present value. The total energy emitted by it then will increase by a factor of
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.*
A body cools from $80^{\circ}\,C$ to $60^{\circ}\,C$ in $5$ minutes. The temperature of the surrounding is $20^{\circ} C$. The time it takes to cool from $60^{\circ}\,C$ to $40^{\circ}\,C$ is........... $s$
A slab consists of two parallel layers of copper and brass of the same thickness and having thermal conductivities in the ratio $1 : 4$ . If the free face of brass is at ${100^o}C$ and that of copper at $0^\circ C $, the temperature of interface is ........ $^oC$
An object is at a temperature of ${400^o}C$. At what temperature would it radiate energy twice as fast? The temperature of the surroundings may be assumed to be negligible
Three rods of same material, same area of crosssection but different lengths $10 \,cm , 20 \,cm$ and $30 \,cm$ are connected at a point as shown. What is temperature of junction $O$ is ......... $^{\circ} C$
In a certain planetary system, it is observed that one of the celestial bodies having a surface temperature of $200 \;K$, emits radiation of maximum intensity near the wavelength $12\; \mu m$. The surface temperature (in $K$) of a nearby star which emits light of maximum intensity at a wavelength $\lambda= 4800\;\mathring A$ is
Three stars $A, B, C$ have surface temperatures $T _{A} ,T _{B}, T _{C}$ respectively. Star $A$ appears bluish, star $B$ appears reddish and star $C$ yellowish. Hence,
Two bars of thermal conductivities $K$ and $3K$ and lengths $1\,\, cm$ and $2\,\, cm$ respectively have equal cross-sectional area, they are joined lengths wise as shown in the figure. If the temperature at the ends of this composite bar is $0\,^oC$ and $100\,^oC$ respectively (see figure), then the temperature $\varphi $ of the interface is......... $^oC$