Two identical rods of length `(L)`, area of cross-sectional `(A)` and thermal conductivity `k` are joined end to end. If temperature difference of free ends is `DeltaT`, the heat `Q_(0)` flows along rods per second. Find the total heat flowing per second along the rods if the two rods are placed parallel and temperature difference of free ends is `DeltaT`. There is no heat loss from curved surface.

Two rods of same length and cross section are joined along the length. Thermal conductivities of first and second rod are K_1 and K_2 . The temperature of the free ends of the first and second rods are maintained at θ_1 and θ_2 respectively. The temperature of the common junction is

Two adiabatic vessels, each containing the same mass m of water but at different temperatures, are connected by a rod of length L, cross-section A, and thermal conductivity K. the ends of the rod are inserted into the vessels, while the rest of the rod is insulated so that .there is negligible loss of heat into the atmosphere. The specific heat capacity of water is s, while that of the rod is negligible. The temperature difference between the two vessels reduces to l//e of its original value after a time, delta t . The thermal conductivity (K) of the rod may be expressed by:

Two rods of same length and cross section are joined along the length. Thermal conductivities of first and second rod are K_(1) and K_(2) . The temperature of the free ends of the first and seconds rods are maintained at theta_(1) and theta_(2) respectively. The temperature of the common junction is

The ends of the two rods of different materials with their lengths, diameters of cross-section and thermal conductivities all in the ratio 1 : 2 are maintained at the same temperature difference. The rate of flow of heat in the shorter rod is 1cals^(-1) . What is the rate of flow of heat in the larger rod:

Three rods of same length and area of cross-section but of thermal conductivities K, 2K and 3K are connected in series in the same order. Free end of the first rod is at 0^(@)C and free end of third rod is at 55^(@)C . In steady state, temperature difference across the middle rod is

Two rods of length l and 2l thermal conductivities 2K and K are connected end to end. If cross sectional areas of two rods are eual, then equivalent thermal conductivity of the system is .

Two rods of the same length and areas of cross-section A_1 and A_2 have their ends at the same temperature. K_1 and K_2 are the thermal conductivities of the two rods. The rate of flow of heat is same in both the rods if-

The end of two rods of different materials with their thermal conductivities, area of cross-section and lengths all in the ratio 1:2 are maintained at the same temperature difference. If the rate of flow of heat in the first rod is 4 cal//s . Then, in the second rod rate of heat flow in cal//s will be