Thermal Properties Questions

Assertion: A body that is a good radiator is also a good absorber of radiation at a given wavelength.Reason: According to Kirchhoff's law the absorptivity of a body is equal to its emissivity at a given wavelength.

On a new scale of temperature (which is linear) called the $W$ scale, the freezing and boiling points of water are $39^{\circ }\text{W}$ and $239^{\circ }\text{W}$ respectively. What will be the temperature on the new scale corresponding to a temperature of $39^{\circ }\text{C}$ on the Celsius scale?

The two ends of a rod of length $L$ and a uniform cross-sectional area $A$ are kept at two temperatures $T_1$ and $T_2$ ($T_1>T_2$). The rate of heat transfer, $\frac{dQ}{dt}$, through the rod in a steady state is given by:

A black body at $227^{\circ }\text{C}$ radiates heat at the rate of $7{\text{Cals/cm}}^2\text{s}$. At a temperature of $727^{\circ }\text{C}$, the rate of heat radiated in the same units will be:

A slab of area $0.36{\text{m}}^2$ and thickness $0.1\text{m}$ has ice on upper surface ($0^{\circ }\text{C}$) and steam on lower surface ($100^{\circ }\text{C}$). In one hour $4.8\text{kg}$ of ice melts. Thermal conductivity of slab is: ($L_f=3.36\times 10^5{\text{J kg}}^{-1}$)

Liquid oxygen at $50\text{K}$ is heated to $300\text{K}$ at constant pressure of $1\text{atm}$. The rate of heating is constant. Which one of the following graphs represents the variation of temperature with time?

If the radius of a star is $R$ and it acts as a black body, what would be the temperature of the star, in which the rate of energy production is $Q$?

$4.0\text{g}$ of a gas occupies $22.4$ liters at NTP. The specific heat capacity of the gas at constant volume is $5.0{\text{J K}}^{-1}{\text{mol}}^{-1}$. If the speed of sound in this gas at NTP is $952{\text{m s}}^{-1}$, then the molar heat capacity at constant pressure is (Take gas constant $R=8.3{\text{J K}}^{-1}{\text{mol}}^{-1}$):

The value of coefficient of volume expansion of glycerin is $5\times 10^{-4}{\text{K}}^{-1}$. The fractional change in the density of glycerin for a rise of $40^{\circ }\text{C}$ in its temperature is: