body radiates energy $5W$ at a temperature of ${127^o}C$. If the temperature is increased to ${927^o}C$, then it radiates energy at the rate of ...... $W$
Medium
Download our app for free and get started
(c) Rate of energy $\frac{Q}{t} = P = A\varepsilon \sigma {T^4}$
==> $P \propto {T^4}$
==> $\frac{{{P_1}}}{{{P_2}}} = {\left( {\frac{{{T_1}}}{{{T_2}}}} \right)^4}$$ = {\left( {\frac{{927 + 273}}{{127 + 273}}} \right)^4}$$ \Rightarrow {P_1} = 405\;W$
Download our appand get started for free
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.*
Similar Questions
- 1Two identical square rods of metal are welded end to end as shown in figure $(i)$ , $20$ calories of heat flows through it in $4$ minutes. If the rods are welded as shown in figure $(ii)$, the same amount of heat will flow through the rods in ....... $\min.$View Solution
- 2The temperature at which a black body of unit area loses its energy at the rate of $1$ joule/second isView Solution
- 3The rate of heat flow through the cross-section of the rod shown in figure is ($T_2 > T_1$ and thermal conductivity of the material of the rod is $K$)View Solution
- 4An incandescent bulb has a thin filament of tungsten that is heated to high temperature by passing an electric current. The hot filament emits black-body radiation. The filament is observed to break up at random locations after a sufficiently long time of operation due to non-uniform evaporation of tungsten from the filament. If the bulb is powered at constant voltage, which of the following statement($s$) is(are) true?View Solution
($A$) The temperature distribution over the filament is uniform
($B$) The resistance over small sections of the filament decreases with time
($C$) The filament emits more light at higher band of frequencies before it breaks up
($D$) The filament consumes less electrical power towards the end of the life of the bulb
- 5Calculate radiation power for sphere whose temperature is $227^{\circ} C$ and radius $2\, m$ and emissivity $0.8$ (in $W$)View Solution
- 6View SolutionAs compared to the person with white skin, the person with black skin will experience
- 7Five rods of same dimensions are arranged as shown in the figure. They have thermal conductivities $K1, K2, K3, K4$ and $K5$ . When points $A$ and $B$ are maintained at different temperatures, no heat flows through the central rod ifView Solution
- 8A composite metal bar of uniform section is made up of length $25 cm$ of copper, $10 cm$ of nickel and $15 cm$ of aluminium. Each part being in perfect thermal contact with the adjoining part. The copper end of the composite rod is maintained at ${100^o}C$ and the aluminium end at ${0^o}C$. The whole rod is covered with belt so that there is no heat loss occurs at the sides. If ${K_{{\rm{Cu}}}} = 2{K_{Al}}$ and ${K_{Al}} = 3{K_{{\rm{Ni}}}}$, then what will be the temperatures of $Cu - Ni$ and $Ni - Al$ junctions respectivelyView Solution
- 9The figure shows a system of two concentric spheres of radii $r_1$ and $r_2$ and kept at temperatures $T_1$ and $T_2$, respectively. The radial rate of flow of heat in a substance between the two concentric spheres is proportional toView Solution
- 10A black body is at a temperature $300 K$ . It emits energy at a rate, which is proportional toView Solution