Three rods of copper, brass and steel are welded togeher to from a Y -shaped structure. Area of cross-section of each rod `=4 cm^(2)`. End of copper rod is maintained at `100^(@)C` whereas the ends of brass and steel are at `0^(@)C` . Lengths of copper, brass and steel rods are 46, 13 and 12 cm respectively. The rods are thermally insulated from surroundings except at ends. Thermal conductivities of copper, brass and steel are `0.92, 0.26` and `0.12` CGS units respectively. Rate of heat flow through copper rod is
A
`4.8 cal//s`
B
`6.0 cal//s`
C
`1.2 cal//s`
D
`2.4 cal//s`
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Three rods of copper, brass and steel are welded together to form a Y -shaped structure. The cross-sectional area of each rod is 4 cm^2 . The end of copper rod is maintained at 100^@C and the ends of the brass and steel rods at 80^@C and 60^@C respectively. Assume that there is no loss of heat from the surfaces of the rods. The lengths of rods are : copper 46 cm, brass 13 cm and steel 12 cm. (a) What is the temperature of the junction point? (b) What is the heat current in the copper rod? K(copper) = 0.92, K (steel) = 0.12 and K(brass) = 0.26 cal//cm-s^@C .
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) .
Coefficient of liner expansion of brass and steel rods are alpha_(1) and alpha_(2) . Length of brass and steel rods are l_(1) and l_(2) respectively. If (l_(2)-l_(1)) is maintained same at all temperatures, which one of the following relations hold good ?
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
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 .
Two ends of a conducting rod of varying cross-section are maintained at 200^(@)C and 0^(@)C respectively. In steady state:
A copper rod of length 75 cm and an iron rod of length 125cm are joined together end to end . Both are of circular cross section with diameter 2 cm . The free ends of the copper and iron are maintained at 100^@C and 0^@C respectively . The surface of the bars are insulated thermally . The temperature of the copper -iron junction is [Thermal conductivity of the copper is 386.4 W//m-K and that of iron is 48.46W//m-K ].
Figure shows a steel rod joined to a brass rod. Each of the rods has length of 31 cm and area of cross-section 0.20 cm^(2) . The junction is maintained at a constant temperature 50^(@)C and the two ends are maintained at 100^(@)C . The amount of heat taken out from the cold junction in 10 minutes after the steady state is reached in n xx 10^(2)J . Find 'n' the thermal conductivities are K_(steel) = 46 W//m-^(@)C and K_(brass) = 109 W//m-^(@)C .
The difference between lenghts of a certain brass rod and of a steel rod is claimed to be constant at all temperatures. Is this possible?
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