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प्रश्न
Answer the following question.
Define coefficient of thermal conductivity.
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उत्तर
The coefficient of thermal conductivity of a material is defined as the quantity of heat that flows in one second between the opposite faces of a cube of side 1 m, the faces being kept at a temperature difference of 1°C (or 1 K).
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संबंधित प्रश्न
Answer the following question.
Derive its expression for the coefficient of thermal conductivity.
Answer the following question.
Give any four applications of thermal conductivity in everyday life.
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Explain the term thermal resistance. State its SI unit and dimensions.
Solve the following problem.
Which will require more energy, heating a 2.0 kg block of lead by 30 K or heating a 4.0 kg block of copper by 5 K?
(slead = 128 J kg–1 K–1, `"s"_"copper"` = 387 J kg–1 K–1)
Solve the following problem.
The rate of flow of heat through a copper rod with temperature difference 30 °C is 1500 cal/s. Find the thermal resistance of copper rod.
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A slab consist of two parallel layers of copper and brass of the same thickness and having thermal conductivities in the ratio 1 : 4. If the free face of brass is at 100°C and that of copper at 0°C, the temperature of interface is ______.
Two rectangular blocks A and B of different metals have same length and same area of cross-section. They are kept in such a way that their cross-sectional area touch each other. The temperature at one end of A is 100°C and that of B at the other end is 0°C. If the ratio of their thermal conductivity is 1 : 3, then under steady state, the temperature of the junction in contact will be ______.
A thin square steel plate with each side equal to 10 cm is heated by a blacksmith. The rate of radiated energy by the heated plate is 1134 watts. The temperature of the hot steel plate is ______.
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Two metallic blocks M1 and M2 of same area of cross-section are connected to each other (as shown in figure). If the thermal conductivity of M2 is K then the thermal conductivity of M1 will be ______. [Assume steady state heat conduction]
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Two rods of the same material, same length and same radius transfer a given amount of heat in t second when they are joined end-to-end. When the rods are joined one above the other, then they will transfer the same heat in the same conditions in time ______.
Through which mode does heat transfer take place in solids?
In which mode of heat transfer do the molecules physically move from one place to another?
Which mode of heat transfer does NOT require any material medium?
At what speed do electromagnetic waves travel in space during radiation?
Which of the following correctly arranges the three modes of heat transfer from slowest to fastest?
Three identical heat conducting rods are connected in series as shown in the figure. The rods on the sides have thermal conductivity 2K while that in the middle has thermal conductivity K. The left end of the combination is maintained at temperature 3T and the right end the at T. The rods are thermally insulated from outside. In steady state, temperature at the left junction is T1 and that the right junction is T2. The ratio T1/2 T is:
