TEMPERATURE GRADIENT

In the figure-II temperature of inner surface of cylinder is 0^@C and temperature of outer surface is 100^@C . In figure-I temperature of one end of cylinder is 100^@C while another end is at 0^@C (dT)/(dr) =temperature gradient in radial direction at steady state in figure -II (dT)/(dl) =temperature gradient in linear direction at steady state in figure -I . both cylinder are made of uniform material

Diffusion rates are affected by : (a) Pressure (b) Temperature (c) Concentration gradient (d) More than one option is correct

The thermal conductivites of copper, mercury and glass are respectively K_(C),K_(M)andK_(G) such that K_(C)gtK_(M)gtK_(G) . If the same quantity of heat flows per second per unit area of each and the corresponding temperature gradients are X_(C),X_(M)andX_(G) then

A heat flux passes through a gas from a heated plate with a temperature T_1 to a cold plate with a temperature T_2 . The linear dimensions of the plates are large compared to the distance between them. Is the temperature gradient the same along the entire heat flux? Why when measuring the thermal conductivity coefficient must we place the plates horizontally, with the plate with the higher temperature placed above the one with the lower temperature?

Two rods of different materials having differnet lengths and same cross sectional areas are joined end to end in a straight line. The free ends of this compound rod are maintained at different temperatures The temperature gradient in each rod will be .

Explain the term temperature gradient. The two ends of a metal bar are maintained at two different consistant temperatures. On a single graph draw sketches to show the variation of temperature along the bar when its surface is (i) perfectly lagged and (ii) unlagged. Explain the shape of the two sketches.

A tall cylindrical vessel with gaseous nitrogen is located in a uniform gravitational field in which the free-fall acceleration is equal to g . The temperature of the nitrogen varies along the height h so that its density is the same throught the volume. find the temperature gradient dT//dh .

A uniform copper bar 100 cm long is insulated on side, and has its ends exposed to ice and steam respectively. If there is a layer of water 0.1 mm thick at each end, calculate the temperature gradient in the bar. K_(Cu)=1.04 and K_(water)=0.0014 in CGS units.