A cubical box of volume `216cm^(3)` is made up of `0.1cm thick wood, The inside is heated electrically by 100W heater. It is found that the temperature difference between the inside and the outside surface `5^(@)C` . In steady state . Assuming that the entire electrically energy spent appears as heat, find the thermal conductivity of the material of the box.

A 100 W heater is placed in a cubical container of edge length 6xx10^(-2)m. The wall thick ness of the container is 1 mm. If inside and outside temperature in steady state are 30^(@)C. and 25^(@)C, find the thermal conductivity of the material of the box.

A cylindrical metallic pipe is 14 cm long. The difference between the outside and inside surface is 44 cm^(2) . If the pipe is made up of 99 cubic cm of metal, find the outer and inner radii of the pipe.

A cylindrical metallic pipe is 14 cm long. The difference between the outside and inside surface is 44 cm^(2) . If the pipe is made up of 99 cubic cm of metal, find the outer and inner radii of the pipe.

1.56 xx 10 ^(5) J of heat is conducted through a 2 m^(2) wall of 12 cm thick in one hour. Temperature difference between the two sides of the wall is 20 ^(@) C The thermal conductivity of the material of the wall is (in W m^(-1) K^(-1))

‘cold box’ in the shape of a cube of edge 50 cm is made of ‘thermocol’ material 4.0 cm thick. If the outside temperature is 30^(@)C the quantity of ice that will melt each hour inside the ‘cold box’ is : (the thermal conductivity of the thermocol material is 0.050 W//mK)

A cold box in the shape of a cube of edge 50 cm is made of ‘thermocol’ material 4.0 cm thick. If the outside temperature is 30^(@)C the quantity of ice that will melt each hour inside the ‘cold box’ is : (the thermal conductivity of the thermocol material is 0.050 W//mK)

A closed cubical box is made of perfectly insulating material and the only way for heat to enter or leave the box is through two solid cylindrical metal plugs, each of cross sectional area 12cm^(2) and length 8cm fixed in the opposite walls of the box. The outer surface of one plug is kept at a temperature of 100^(@)C . while the outer surface of the plug is maintained at a temperature of 4(@)C . The thermal conductivity of the material of the plug is 2.0Wm^(-1).^(@)C^(-1) . A source of energy generating 13W is enclosed inside the box. Find the equilibrium temperature of the inner surface of the box assuming that it is the same at all points on the inner surface.