Thermal Propert...

Keeping the number of moles, volume and pressure the same, which of the following are the same for all ideal gas?

A metal ball immersed in water weighs $$w_1$$ at $$5^{\circ}C\;and\;w_2$$ at $$50^{\circ}C$$. The coefficient of cubical expansion of metal is less than that of water. Then

A black body is at $$(727)^{0}C$$. It emits energy at a rate which is proportional to:

Three rods $$A,B$$ and $$C$$ have the same dimensions. Their thermal conductivities $$k_A, \space k_B$$ and $$k_C$$ respectively. $$A$$ and $$B$$ are placed end to end, with the free ends kept at a certain temperature difference. $$C$$ is placed separately with its ends kept at same temperature difference. The two arrangements conduct heat at the same rate $$k_C$$ equal to

An insulated cylindrical tube of an air-conditioner's condenser contains a hot fluid. Temperature of fluid is $${500}^{o}C$$ and outside temperature is $${40}^{o}C$$. Hot fluid tube is very thin and is covered with $$3$$ layers of different insulating materials. Cross-section of the tube is as shown in figure. Given $${ r }_{ 1 }=1cm;{ r }_{ 2 }=2cm;{ r }_{ 3 }=8cm;{ r }_{ 4 }=64cm$$
$${ K }_{ A }=1W/{ m }^{ -1 }\: { _{  }^{ o }{ C } }^{ -1 };{ K }_{ B }=2W/{ m }^{ -1 }\: { _{  }^{ o }{ C } }^{ -1 };{ K }_{ C }=3W/{ m }^{ -1 }\: { _{  }^{ o }{ C } }^{ -1 }$$
Heat loss per unit length (in watts) of tube will be:

The value of $$C_p-C_v$$ is 1.09 R for a gas sample in state A and is 1.00 R in state R. Let $$T_A, T_B$$ denote the temperature and $$p_A$$ and $$p_B$$ denote the pressure of the states A and B respectively. Then

Two slabs $$A$$ and $$B$$ of equal surface area are placed one over the other such that their surfaces are completely in contact. The thickness of slab $$A$$ is twice that of $$B$$. The coefficient of thermal conductivity or slab $$A$$ is twice that of $$B$$. The first surface of slab $$A$$ is maintained at $$100$$, while the second surface of slab $$B$$ is maintained at $$25$$. The temperature at the contact of their surfaces is

A thermocol box has a total wall area (including the lid) of $$1.0{ m }^{ 2 }$$ and wall thickness of $$3cm$$. It is filled with ice at $${ 0 }^{ o }C$$. If the average temperature outside the box is $${ 30 }^{ o }C$$ throughout the day, the amount of ice that melts in one day is
(Use $${ K }_{ thermocol }=0.03W/mK,{ L }_{ fusion(ice) }=3.00\times { 10 }^{ 5 }J/kg\quad $$

A shining metallic ball with a small black spot on its surface is heated to a very high temperature and then quickly taken to a dark room. Then:

A rod of length $$l$$ with thermally insulated lateral surface consists of material whose heat conductivity coefficient varies with temperature as $$k = \alpha/ T$$, where $$\alpha$$ is a constant. The ends of the rod are kept at temperature $$T_{1}$$ and $$T_{2}$$. Find the function $$T(x)$$, where $$x$$ is the distance from the end whose temperature is $$T_{1}$$, and the heat flow density.