Calculate the rate of loss of heat through a glass window of area `1000 cm^(2)` and thickness 0.4 cm when temperature inside is `37^(@)C` and outside is `-5^@)C` . Coefficient of thermal conductivity of glass is `2.2 xx 10^(-3) cal s^(-1) cm^(-1) K^(-1)`.

For a glass window of area 1500 cm^2 and thickness 0.5 cm, determine the rate of loss of heat if the temperature inside the window is 35^@C and outside is -2^@C . Take, coefficient of thermal conductivity of glass = 2.2 xx 10^(-3) cal s^(-1) cm^(-1) K^(-1)

A heater of resistance 20 Omega is used to heat a room at 10^@C and is connected to 220 V mains. The temperature is uniform inside the room and heat is transmitted outside the room through a glass window of area 1.2 m^2 and thickness 0.1 cm. If T^@C is the temperature outside and thermal conductivity of glass is 0.2 cal s^(-1) m^(-1) ""^@C^(-1) , then find the value of 10T - 75 close to nearest integer.

Calculate the quantity of heat conducted through 2m^(2) of a brick wall 12cm thick in 1 hour if the temperature on one side is 8^(@)C and on the other side is 28^(@)C . (Thermal conductivity of brick =0.13Wm^(-1)K^(-1) )

Estimate the rate at which ice would melt in a wooden box 20 mm thick and of inside measurement 200 cm x 100 cm x 100 cm assumming that external temperature is 27^(@)C and coefficient of thermal conductivity of wood is 0.0004 cal s^(-1) cm^(-1) .^(@)C^(-1) .

A room at 20^@C is heated by a heater of resistence 20 ohm connected to 200 VV mains. The temperature is uniform throughout the room and the heati s transmitted through a glass window of area 1m^2 and thickness 0.2 cm. Calculate the temperature outside. Thermal conductivity of glass is 0.2 cal//mC^@ s and mechanical equivalent of heat is 4.2 J//cal .

The area of the glass of a window of a room is 10 m^(2) and thickness 2 mm . The outer and inner temperature are 40^(@)C and 20^(@)C respectively. Thermal conductivity of glass in MKS system is 0.2. The heat flowing in the room per second will be

A room is to be maintained at a constant temperature of 30^@C and is heated by a heater of resistance 10 Omega connected to 210 V mains supply. Heat is transmitted outside through a window of thickness 0.3 cm and area 2 m^2 What will be temperature outside the window? Thermal conductivity of glass = 0.3 cal s^(-1) m^(-1) ""^@C^(-1)

A double pan window used for insulating a room thermally from outside consists of two glass sheets each of area 1 m^(2) and thickness 0.01m separated by 0.05 m thick stagnant air space. In the steady state, the room-glass interface and the glass-outdoor interface are at constant temperatures of 27^(@)C and 0^(@)C respectively. The thermal conductivity of glass is 0.8 Wm^(-1)K^(-1) and of air 0.08 Wm^(-1)K^(-1) . Answer the following questions. (a) Calculate the temperature of the inner glass-air interface. (b) Calculate the temperature of the outer glass-air interface. (c) Calculate the rate of flow of heat through the window pane.

A room has s window fitted with a single 0.1mxx2.0m glass of thickness 2mm. (a) Calculate the rate of heat flow through the clossed window when the temperature inside the room is 32^(@)C and that outside is 40^(@)C . (b) The glass is now replaced by two glasspance, each having a thickness of 1mm and separated by a distance of 1mm. Calculalte the rate of heat flow under the same condition of temperature. Thermal conductivity of window glass =1.0Js^(-1)m^(-1) ^(@)C^(-1) and that of air =0.025Js^(-1)m^(-1) ^(@)C^(-1) .