Thermal Propert...

Two rods A and B of same length and radius are joined together. the thermal conductivity of A and B are $$2K$$ and $$K$$. Under steady state conditions, if the temperature difference between the open ends of A and B is $$36^{\circ}C$$, the temperature difference across 'A' is:

If the temperature of a hot body is increased by 50% then the increase in the quantity of emitted heat radiation will be

A copper block A of mass 500 gm and $$S_p$$ heat 0.1 cal/gm/$$ ^ { \circ } C$$ is heated from $$30 ^ { \circ } C \text { to } 40 ^ { \circ } C$$. Another identical copper block B of same mass is heated from $$35 ^ { \circ } C \text { to } 40 ^ { \circ } C$$. The ratio of their thermal capacities is: 

Two identical square rods of metal are welded end to end as shown in figure (a). $$20$$ calories of heat flows through it in $$4$$ minutes. if the rods are welded as shown in figure (b), the same amount of heat will flow through the rods in

In a container of negligible heat capacity $$100 gm$$ of a liquid at $$20 ^ { \circ } \mathrm { C }$$ is heated. Specific heat of the liquid varies with temperature given as $$s = ( 100 T + 500 ) J / k g ^ { \circ } C$$ where $$T$$ is in$$^{ \circ  }C$$ . Find the amount of heat required to raise the temperature of the liquid to $$40 ^ { \circ } \mathrm { C }$$

A copper bar $$10\ cm$$ long has its ends passed against copper tanks at $$0^{o}C$$ and $$100^{o}C$$. The ends are separated by layers of dust $$0.1\ mm$$ thick. If conductivity of dust is $$0.001$$ times that of copper, the temperature of end $$P$$ and $$Q$$ of bar are [Take rate of flow of heat constant from $$P$$ to $$Q$$]

The pressure of the gas contained in a closed vessel is increased by $$0.4\%$$ when heated by $$1^oC$$. The initial temperature of the gas must be

One end of a thermally insulated rod is kept at a temperature $$T_1$$ and the other at $$T_2$$. The rod is composed of two sections of lengths $$L_1$$ and $$L_2$$ and thermal conductivities $$k_1$$ and $$k_2 $$ respectively. The temperature at the interface of the sections is 

When is the temperature at its peak? what is its value then?

A crystal has a coefficient of expansion $$1.3\times 10^{-8}$$ in one direction and $$2.31\times 10^{-7}$$ in every direction at right angles to it. Then the cubical coefficient of expansion is :