Two rods of same length and material transfer a given amount of heat in $12\, seconds$ , when they are joined end to end. But when they are joined in series, then they will transfer same heat in same conditions in........ $\sec$
$24$
$3$
$1.5$
$48$
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 $0.25$ ?
Three rods $A, B,$ and $C$ of thermal conductivities $K, 2K$ and $4K$, cross-sectional areas $A, 2A$ and $2A$ and lengths $2l, l$ and $l$ respectively are connected as shown in the figure. If the ends of the rods are maintained at temperatures $100\,^oC$, $50\,^oC$, and $0\,^oC$ respectively, then the temperature $\theta$ of the junction is
Calculate the surface temperature of the planet, if the energy radiated by unit area in unit time is $5.67 \times 10^4\,watt$ : (Planet may be assumed to black body)
Six identical conducting rods are joined as shown in figure. Points $A$ and $D$ are maintained at temperatures $200\,^oC$ and $20\,^oC$, respectively. the temperature of junction $B$ will be ........ $^oC$
Newton's law of cooling is used in laboratory for the determination of the ...........