Solar radiation emitted by the sun resembles that emitted by a black body at a temperature of $6000\, K$. Maximum intensity is emitted at a wavelength of about $4800\,\mathop A\limits^o $. If the sun was cooled down from $6000\, K$ to $3000\, K$, then the peak intensity would occur at a wavelength of ......... $\mathop A\limits^o $
$4800$
$9600$
$2400$
$19200$
The temperature of furnace is $200\,^oC$, in its spectrum the maximum intensity is obtained at about $400\,\mathop A\limits^o $, If the maximum intensity is at $200\,\mathop A\limits^o $. Calculate the temperature of the furnace in ${}^oC$. ......... $^oC$
Two rods of same material have same length and area. The heat $\Delta Q$ flows through them for $12\, minutes$ when they are jointed in series. If now both the rods are joined in parallel, then the same amount of heat $\Delta Q$ will flow in ........ $\min$.
In a composite rod, when two rods of different lengths and of the same area are joined end to end, then if $K$ is the effective coefficient of thermal conductivity ; $\frac{{{\ell _1} + {\ell _2}}}{K}$ is equal to
The power radiated by a black body is $P$ and it radiates maximum energy around the wavelength $\lambda_0$. If the temperature of the black body is now changed so that it radiates maximum energy around wavelength $\frac{3}{4}\lambda_0$, the power radiated by it will increase by a factor of
A wall has two layers $A$ and $B$ , each made of a different material. Both the layers have the same thickness. The thermal conductivity of the material of $A$ is twice that of $B$ . Under thermal equilibrium, the temperature difference across the wall is $36\,^oC$. The temperature difference across the layer $A$ is ......... $^oC$