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Two conducting slabs of thermal conductivities K1 and K2 are joined as shown in the figure. The temperature of the ends of slab are `θ_1 and θ_2 (θ_1 > θ_2)`. Find the final temperature of

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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The ends of the two rods of different materials with their thermal conductivities, radii of cross – section and length in the ratio 1:2 are maintained at the same temperature difference. If the rate of flow of heat through the larger rod is 4 cal |s, what is the rate of flow through the shorter

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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What are thermal radiation? Write its properties of thermal

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An indirectly heated filament is radiating maximum energy of wavelength `2.16xx 10^(-7)m`. Find the net amount of heat energy lost per second per unit area, the temperature of surrounding air is `13^oC`. Given `b = 2.88xx10^(-3) mk, σ = 5.77xx10(-8)

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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Animals in the forest find shelter from cold in holes in the snow.

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A brass boiler has a base area of `0.15m^2` and thickness 1.0cm. It boils water at the rate of 6kg| min when placed on a gas stove, Estimate the temperature of the part of flame in contact with the boiler. Thermal conductivity of brass `= 10^9J|s|m|'^oC`, heat of vaporization of water `=

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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How do you explain heating of rooms based on principle of

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If the radiation from the moon gives maxima at `λ = 4700 A^o and λ = 14xx10^(-6)m`. What conclusion can be drawn from the above

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Differentiate between conduction, convection and

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The tile floor feels colder than the wooden floor even though both floor materials are at same temperature.

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A spherical black body of radius 12cm radiates 450w power at 500k. If the radius were halved and the temperature doubled, what would be the power

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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A cylinder of radius R made of a material of thermal conductivity K1 is surrounded by a cylindrical shell of inner radius R and other radius 2R made of material of thermal conductivity K2. The 2 ends of combined system are maintained at two different temperatures. There is no loss of heat across the clinical surface and the system is in steady state calculate the effective thermal conductivity of the

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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A room has a 4m x 4m x10cm concrete roof `(K_1 = 1.26w|m|'^oC)`. At some instant, the temperature outside is `46^oc` and radius `32^oc`. 1) Calculate amount of heat flowing per second into the room through the roof. 2) If bricks `(K_2 – 0.56w |m|'^oc)` of thickness 7.5cm are laid down on roof, calculate the new rate of heat flow under the same temperature

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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A bar of copper of length 75cm and a bar of length 125cm are joined end to end. Both are of circular cross – section with diameters 2cm. The free ends of copper and steel are maintained at `100^oc and 0^oc` respectively. The surfaces of the bars are thermally insulated. What is the temperature of copper – steel junction? Thermal conductivity of copper `= 9.2xx10^(-2)k cal |m|'^oc|s` and that of steel is `1.1xx10^(-2) k

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Why is it hotter at the same distance over the top of the fire than in front of

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A metal rod of length 20cm and diameter 2cm is covered with a non-conducting substance. One of it ends is maintained at `100^oc` while the other is at `0^oc`. It is found that 25g of ice melts in 5 min calculate coefficient of thermal conductivity of

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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Calculate the temperature in Kelvin at which a perfectly black body radiates at the rate of 5.67

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Does the working of an electric refrigerator defy second law of

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A Carnot engine absorb `6×10^5` cal at `227^oc` calculate work done per cycle by the engine if it sink is at

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How does second law of thermodynamics explain expansion of

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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