GATE ME 2005 | Conduction Question 33 | Heat Transfer

GATE ME 2005

MCQ (Single Correct Answer)

-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

$${T \over x}$$

$${{\partial T} \over {\partial x}}$$

$${{{\partial ^2}T} \over {\partial x\partial t}}$$

$${{{\partial ^2}T} \over {\partial {x^2}}}$$

GATE ME 2004

MCQ (Single Correct Answer)

-0.3

One dimensional unsteady state heat transfer equation for a sphere with heat generation at the rate $$'{q_g}',$$ can be written as

$${1 \over {r^2}}\,{\partial \over {\partial r}}\left( {r{{\partial T} \over {\partial r}}} \right) + {q \over k} = {1 \over \alpha }\,{{\partial T} \over {\partial t}}$$

$${1 \over {r^2}}\,{\partial \over {\partial r}}\left( {{r^2}{{\partial T} \over {\partial r}}} \right) + {q \over k} = {1 \over \alpha }\,{{\partial T} \over {\partial t}}$$

$${{{\partial ^2}T} \over {\partial {r^2}}} + {q \over k} = {1 \over \alpha }\,{{\partial T} \over {\partial t}}$$

$${{{\partial ^2}} \over {\partial {r^2}}}\left( {rT} \right) + {q \over k} = {1 \over \alpha }\,{{\partial T} \over {\partial t}}$$

GATE ME 2001

MCQ (Single Correct Answer)

-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

$$a\,\,b\,\,c\,\,d$$

$$b\,\,c\,\,a\,\,d$$

$$d\,\,a\,\,b\,\,c$$

$$d\,\,c\,\,b\,\,a$$

GATE ME 1996

MCQ (Single Correct Answer)

-0.3

For a given heat flow and for the same thickness, the temp drop across the material will be maximum for

Copper

Steel

Glass wool

Refractory brick