Home
Class 11
PHYSICS
Calculate the rate of loss of heat throu...

Calculate the rate of loss of heat through a glass window of area 1000 cm2 and thickness of 4 mm, when temperature inside is `27^@ C` and outside is `-5^@ C`. Coefficient of thermal conductivity of glass is 0.022 cal/ s` cm^@ `C.

Text Solution

Verified by Experts

Given
A= 1000 `cm^2 = 1000 xx 10^(-4) m^2`
` K=0.022 cal // s cm^@ C = 0.0222 xx 10^2 cal // m^@ C`
` x=4 mm = 0.4 xx 10^(-2) m`
` T_1 = 27^@ C , T_2 =- 5^@ C `
From Eq. ( 7.34 ) , we have
` Q = (KA (T_1-T_2)t)/( x)`
` therefore (Q)/(t )= (KA (T_1-T_2))/(x)`
`= ( 0.022 xx 10^2 xx 1000 xx 10^(-4) xx ( 27 - (-5)))/( 0.4 xx 10^(-2))`
`= 1.76 xx 10^3 cal //s = 1.76 "kcal" //s `
Promotional Banner

Similar Questions

Explore conceptually related problems

What is the rate of energy loss in watt per square metre through a glass window 5 mm thick if outside temperature is -20^@ C and inside temperature is 25^@ C ? ( k_("glass") = 1 W//m K )

The difference in temperature between two sides of a glass plate 0.3 mm thick is 25^@C . If the area of one side surface is 10 m^2 , calculate the heat conducted per second through the plate. The thermal conductivity of glass is 0.84 J//s m K.

A wall of a room has dimensions of 6m xx 4m . It is 60 cm thick. Its thermal conductivity is is 2. If the temperature inside and outside is 20^@C and -5^@C respectively the amount of heat conducted every hour is about

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.

Calculate the capacitance of a parallel plate condenser of two plates of area 10^4 cm^2 each separated by 4 mm thick glass sheet of k =4.

Calculate the energy radiated is one minutes by a black body of surface area 400cm^2 ,when it is maintained at 127^@C .

Calculate the energy radiated in one minute by a black body of surface area 100 cm^2 when it is maintained at 227^@C ( sigma= 5.67 xx 10^-8 J/m^2sK^4 )

Calculate the thermal resistance of 1 square metre of window glass pane that is 0.5 cm thick (k=0.6frac(W)(m^@C))

Find the temperature difference between two sides of a steel plate 4 cm thick, when heat is transmitted through the plate at the rate of 400 kcal per minute per square metre at steady rate. Thermal conductivity of steel is 0.026 kcal//m.s. k .