Figure shows three different arrangements of materials $1, 2$ and $3$ to form a wall. Thermal conductivities are $k_1 > k_2 > k_3$ . The left side of the wall is $20\,^oC$ higher than the right side. Temperature difference $\Delta T$ across the material $1$ has following relation in three cases
A$\Delta T_a > \Delta T_b > \Delta T_c$
B$\Delta T_a = \Delta T_b = \Delta T_c$
C$\Delta T_a = \Delta T_b > \Delta T_c$
D$\Delta T_a = \Delta T_b < \Delta T_c$
Easy
Download our app for free and get started
B$\Delta T_a = \Delta T_b = \Delta T_c$
b In all the three cases, temperature difference along the combination is same. Thus, heat current in all the three cases are same $\Rightarrow $ temperature difference across any layer in all the three case is same
Download our app
and get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
Two spheres of different materials one with double the radius and one-fourth wall thickness of the other, are filled with ice. If the time taken for complete melting ice in the large radius one is $25$ minutes and that for smaller one is $16$ minutes, the ratio of thermal conductivities of the materials of larger sphere to the smaller sphere is
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 length $l_1$ and $l_2$ and thermal conductivities $K_1$ and $K_2$ respectively. The temperature at the interface of the two section is
A sphere, a cube and a thin circular plate, all made of the same material and having the same mass are initially heated to a temperature of $1000°C$ . Which one of these will cool first
A metallic sphere cools from $50^{\circ} C$ to $40^{\circ} C$ in $300 \,s.$ If atmospheric temperature around is $20^{\circ} C ,$ then the sphere's temperature after the next $5$ minutes will be close to$.....C$
The temperature of sun is $5500 K$ and it emits maximum intensity radiation in the yellow region $(5.5 \times {10^{ - 7}}m)$. The maximum radiation from a furnace occurs at wavelength $11 \times {10^{ - 7}}m.$The temperature of furnace is ....... $K$
Two rods one made of copper and other made of steel of the same length and same cross sectional area are joined together. The thermal conductivity of copper and steel are $385\,J\,s ^{-1}\,K ^{-1}\,m ^{-1}$ and $50\,J\,s ^{-1}\,K ^{-1}\,m ^{-1}$ respectively. The free ends of copper and steel are held at $100^{\circ}\,C$ and $0^{\circ}\,C$ respectively. The temperature at the junction is, nearly $.......^{\circ}\,C$
In Newton's experiment of cooling, the water equivalent of two similar calorimeters is $10 $ gm each. They are filled with $350 gm$ of water and $300 gm$ of a liquid (equal volumes) separately. The time taken by water and liquid to cool from ${70^o}C$ to ${60^o}C$ is $3$ min and $95$ sec respectively. The specific heat of the liquid will be ...... $Cal/gm\,^oC$
A partition wall has two layers $A$ and $B$ in contact, each made of a different material. They have the same thickness but the thermal conductivity of layer $A$ is twice that of layer $B$. If the steady state temperature difference across the wall is $60K$, then the corresponding difference across the layer $A$ is ....... $K$