Rate of dissipation of heat by a black body at temperature T is Q . What will be rate of&

English

Gujarati

Hindi

10-2.Transmission of Heat

normal

The rate of dissipation of heat by a black body at temperature $T$ is $Q$. What will be the rate of dissipation of heat by another body at temperature $2\,T$ and emissivity $0.25$ ?

A

$16 \,Q$

B

$4 \,Q$

C

$8 \,Q$

D

$4.5 \,Q$

Solution

$\mathrm{Q}=\sigma \mathrm{A} \mathrm{T}^{4}$

$\mathrm{Q}^{\prime}=\mathrm{e} \sigma \mathrm{A}(2 \mathrm{T})^{4}$

$=0.25 \times 16 \mathrm{Q}=4 \mathrm{Q}$

Standard 11

Physics

Share

Similar Questions

The ratio of thermal conductivity of two rods of different materials is $5 : 4$. The two rods of same area and same thermal resistance will have lengths is the ratio

normal

If the temperature of the sun were to increase from $T$ to $2T$ and its radius from $R$ to $2R$, then the ratio of the radiant energy received on earth to what it was previously will be

normal

The surface temperature of the sun which has maximum energy emission at $500\, nm$ is $6000\, K$. The temperature of a star which has maximum energy emission at $400\, nm$ will be …….. $K$

normal

Two identical conducting rods are first connected independently to two vessels, one containing water at $100^o\ C$ and the other containing ice at $0^o\ C$. In the second case, the rods are joined end to end and connected to the same vessels. Let $q_1$ and $q_2\ g/s$ be the rate of melting of ice in the two cases respectively. The ratio $q_2/q_1$ is

normal

A wall has two layers $A$ and $B,$ each made of different material. Both the layers have the same thickness. The thermal conductivity for $A$ is twice that of $B$ and under steady condition, the temperature difference across the wall is $36\,^oC.$ The temperature difference across the layer $A$ is……. $^oC$

normal