A cubical block of mass `1.0kg` and edge `5.0cm` is heated to `227^(@)C` . It is kept in an evacuated chamber maintained at `27^(@)C` . Assming that the block emits radiation like a blackbody, find the rate at which the temperature of the block will decreases. Specific heat capacity of the material of the block is `400Jkg^(-1)K^(-1)` .

A cubical block of mass `1.0kg` and edge `5.0cm` is heated to `227^(@)

1.	A cubical block of mass `1.0kg` and edge `5.0cm` is heated to `227^(@)C` . It is kept in an evacuated chamber maintained at `27^(@)C` . Assming that the block emits radiation like a blackbody, find the rate at which the temperature of the block will decreases. Specific heat capacity of the material of the block is `400Jkg^(-1)K^(-1)` .
Answer» Rate fo cooling `(dT)/(dt)` = `(esigmaA)/(ms)(T^(4)-T_(0)^(4))` Given, `sigma=1`, Area, `A = 6a^(2)= 6 xx (5xx10^(-2)^(2)=150 xx 10^(-4)m^(2)` Temperature, T = 227 + 273 = 500K `T_(0) (27 + 273) = 300K Given, m = 1kg, s=400J/kg.K `=`6 xx10^(-8) xx 150 xx 10^(-4)[(500)^(4)-(300)^(4)]` `=2.25 xx 10^(-12)xx(625 -8)xx10^(8) = 0.12^(@)C//s`

Discussion

No Comment Found

Related InterviewSolutions

At 1 atmospheric pressure, 1.000 g of water having a volume of `1.000 cm^3` becomes 1671 `cm^3` of steam when boiled. The heat of vaporization of water at 1 atmosphere is `539 cal//g` . What is the change in internal energy during the process ?
A slab consists of two layers of different materials of the same thickness and having thermal conductivities `K_(1)` and `K_(2)`. The equivalent thermal conductivity of the slab isA. K1 + K2B. K1 + K2/2C. 2K1 + K2 /K1 + k2D. K1 + K2/2KK2
The figure given below shows the cooling curve of pure wax material after heating. It cools from A to B and solidifies along BD . If L and C are respective values of latent heat and the specific heat of the liquid wax, the ratio L / C is A. 40B. 80C. 100D. 20
If a body cools down from `80^(@) C`to `60^(@) C` in 10 min when the temperature of the surrounding of the is `30^(@) C` . Then, the temperature of the body after next 10 min will beA. `50^(@) C`B. `48^(@) C`C. `30^(@) C`D. None of the above
A geyser heats water flowing at the rate of `3.0` litre per minute from `27^(@)C` to `77^(@)C`. If the geyser operates on a gas burner and its heat of combustion is `4.0 xx 10^(4) J//g`, then what is the rate of combusion of fuel (approx.)?
Same quantity of ice is filled in each of the two metal container P and Q having the same size, shape and will thickness but make of different materials. The containers are kept in identical surroundings, The ice in P melts completely in time `t_(1)`, whereas in Q takes a time `t_(2)`. The ratio of thermal conductivities of hte materials of P and Q is:A. `t_(2):t_(1)`B. `t_(1):t_(2)`C. `t_(1)^(2):t_(2)^(2)`D. `t_(2)^(2):t_(1)^(2)`
The calories of heat developed in 200 W heater in 7 min is estimatedA. 15000B. 100C. 1000D. 20000
The thickness of a metallic plate is 0.4 cm. The temperature between its two surfaces is `20^(@)C`. The quantity of heat flowing per second is 50 calories from `5cm^(2)` area. In CGS system, the coefficient of thermal conductivity will beA. 0.4B. 0.6C. 0.2D. 0.5
Equal masses of three liquids A, B and C have temperature `10^(@)C, 25^(@)C` and `40^(@)c` respectively. If A and B are mixed, the mixture has a temperature of `15^(@)C`. If B and C are mixed, the mixture has a temperature of `30^(@)C`, if A and C are mixed will have a temperature ofA. `16^(@)C`B. `20^(@)C`C. `25^(@)C`D. `29^(@)C`
Two identical conducting rods AB and CD are connected to a circular conducting ring at two diametrically opposite points B and C, the radius of the ring is equal to the length of rods AB and CD. The area of cross-section, thermal conductivity of the rod and ring are equal. points A and D are maintained at temperatures of `100^(@)C` and `0^(@)C`. temperature at poimt C will be A. `62^(@)C`B. `37^(@)C`C. `28^(@)C`D. `45^(@)C`

Discussion

No Comment Found

Related InterviewSolutions

Reply to Comment