Find the thermal resistance of an aluminium rod of length `20cm` and area of cross section `1cm^(2)` . The heat current is along the length of the rod. Thermal conductivity of aluminium `=200Wm^(-1)K^(-1)` .

The temperature difference between the ends of a rod of aluminium of length 1.0 m and area of cross section 5.0" cm"^(2) is 200^(@)C . How much heat will flow through the rod in 5 minutes ? The coefficient of thermal conductivity of aluminium is 0.2" kJ s"^(-1)" m"^(-1)" "^(@)C^(-1) .

Find the resistance of a copper coil of total wire-length 10m and area of cross section 1.0mm^(2). What would be the resistance of a similar coil of aluminium? The resistivity of copper =1.7xx10^(-8)(Omega)m and that of aluminium 2.6xx10^(-8)(Omega).

An aluminium rod and a copper rod of equal length 1.0 m and cross-sectional area. 1cm^(2) are welded together as shown in figure. One end is kept at a temperature of 20^(@)C and the other at 60^(@)C Calculate the amount of heat taken out per second from the hot end. thermal conductivity of aluminium =200Wm^(-1)C^(-1) and of copper =390Wm^(-1)C^(-1) .

The ends of copper rod of length 1m and area of cross section 1cm^(2) are maintained at 0^(@)C and 100^(@)C . At the centre of rod, there is a source of heat of 32W . The thermal conductivity of copper is 400W//mK

What is the temperature of the steel-copper junction in the steady state system show in Fig. 7(e).17 ? Length of steel rod = 15.0 cm, length of the copper rod = 10.0 cm, temperature of the furnace =300^(@)C , temperature of other end 0^(@)C . The are of cross-section of the steel rod is twice that of the copper rod. (Thermal conductivity of steel =50.2 js^(-1) m^(-1) K^(-1) and of copper =3895 js^(-1) m^(-1) K^(-1) ).

Figure shows an aluminium rod joined to a copper rod. Each of the rods has a length of 20cm and area of cross section 0.20cm^(2) . The junction is maintained at a constant temperature 40^(@)C and the two ends are maintained at 80^(@)C . Calculate the amount of heat taken out from the cold junction in one minute after the steady state is reached. The conductivities are K_(Al)=200Wm^(-1)C^(-1) . and K_(Cu)=400Wm^(-1)C^(-1) .

The ends of a copper rod of length 1m and area of cross-section 1cm^2 are maintained at 0^@C and 100^@C . At the centre of the rod there is a source of heat of power 25 W. Calculate the temperature gradient in the two halves of the rod in steady state. Thermal conductivity of copper is 400 Wm^-1 K^-1 .

The ends of a copper rod of length 1m and area of cross-section 1cm^2 are maintained at 0^@C and 100^@C . At the centre of the rod there is a source of heat of power 25 W. Calculate the temperature gradient in the two halves of the rod in steady state. Thermal conductivity of copper is 400 Wm^-1 K^-1 .

The left end of a copper rod (length= 20cm , Area of cross section= 0.2cm^(2) ) is maintained at 20^(@)C and the right end is maintained at 80^(@)C . Neglecting any loss of heat through radiation, find (a) the temperature at a point 11cm from the left end and (b) the heat current through the rod. thermal conductivity of copper =385Wm^(-1)C^(-1) .

Two parallel plates A and B are joined together to form a compound plate . The thicknesses of the plate are 4.0cm and 2.5cm respectively and the area of cross section is 100cm^(2) for each plate. The thermal conductivities are K_(A)=200Wm^(-1) C^(-1) for plate A and K_(B)=400Wm^(-1) C^(-1) for the plate B. The outer surface of the plate A is maintained at 100^(@)C and the outer surface of the plate B is maintained at 0^(@)C . Find (a) the rate of heat flow through any cross section, (b) the temperature at the interface and (c) the equivalent thermal conductivity of the compound plate.