1
GATE ME 2006
+1
-0.3
In a composite slab, the temperature at the interface (Tinter) between two materials is equal to the average of the temperatures at the two ends. Assuming steady one-dimensional heat conduction, which of the following statements is true about the respective thermal conductivities?
A
$$2{K_1} = {K_2}$$
B
$${K_1} = {K_2}$$
C
$$2{K_1} = 3{K_2}$$
D
$${K_1} = 2{K_2}$$v
2
GATE ME 2005
+1
-0.3
In case of one dimensional heat conduction in a medium with constant properties, $$T$$ is the temperature at position $$x,$$ at time $$t.$$ Then $${{\partial T} \over {\partial t}}$$ is proportional to
A
$${T \over x}$$
B
$${{\partial T} \over {\partial x}}$$
C
$${{{\partial ^2}T} \over {\partial x\partial t}}$$
D
$${{{\partial ^2}T} \over {\partial {x^2}}}$$
3
GATE ME 2004
+1
-0.3
One dimensional unsteady state heat transfer equation for a sphere with heat generation at the rate $$'{q_g}',$$ can be written as
A
$${1 \over {r^2}}\,{\partial \over {\partial r}}\left( {r{{\partial T} \over {\partial r}}} \right) + {q \over k} = {1 \over \alpha }\,{{\partial T} \over {\partial t}}$$
B
$${1 \over {r^2}}\,{\partial \over {\partial r}}\left( {{r^2}{{\partial T} \over {\partial r}}} \right) + {q \over k} = {1 \over \alpha }\,{{\partial T} \over {\partial t}}$$
C
$${{{\partial ^2}T} \over {\partial {r^2}}} + {q \over k} = {1 \over \alpha }\,{{\partial T} \over {\partial t}}$$
D
$${{{\partial ^2}} \over {\partial {r^2}}}\left( {rT} \right) + {q \over k} = {1 \over \alpha }\,{{\partial T} \over {\partial t}}$$
4
GATE ME 2001
+1
-0.3
In descending order of magnitude, the thermal conductivity of $$(a)$$ Pure iron, $$(b)$$ liquid water, $$(c)$$ saturated water vapour, and $$(d)$$ aluminum can be arranged as
A
$$a\,\,b\,\,c\,\,d$$
B
$$b\,\,c\,\,a\,\,d$$
C
$$d\,\,a\,\,b\,\,c$$
D
$$d\,\,c\,\,b\,\,a$$
GATE ME Subjects
EXAM MAP
Medical
NEET