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Physics - Heat & Thermo Question with Solution | TestHub

PhysicsHeat & ThermoRadiationEasy2 minPYQ_2017

PhysicsEasysingle choice

A spherical black body with a radius of $12 cm$ radiates $450 W$ power at $500 K$ . If the radius were halved and the temperature doubled, the power radiated in watt would beNEET 2017

Options:

Answer:

Solution:

By Stefan's law rate of heat radiation from a black body $= σ A T^{4}$

$\Rightarrow$ Rate of power loss

$r \propto R^{2} T^{4}$

$\frac{r_{1}}{r_{2}} = \frac{R_{1}^{2} T_{1}^{4}}{R_{2}^{2} T_{2}^{4}}$

$= 4 \times \frac{1}{16}$

$\frac{450}{r_{2}} = \frac{1}{4}$

$r_{2} = 1800 w a t t$

Stream:NEETSubject:PhysicsTopic:Heat & ThermoSubtopic:Radiation

⏱ 2mℹ️ Source: PYQ_2017

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