1
GATE ME 2004
+2
-0.6
A spherical thermocouple junction of diameter $$0.706 mm$$ is to be used for the measurement of temperature of a gas stream. The convective heat transfer co-efficient on the bead surface is $$400W/{m^2}K.$$ Thermo-physical properties of thermocouple material are
$$k = 20W/mK,$$ $$C = 400J/kgK$$ and $$\rho = 8500\,\,kg/{m^3}.$$ If the thermocouple initially at $${30^ \circ }C$$ is placed in a hot stream of $${300^ \circ }C$$ the time taken by the bead to reach $${298^ \circ }C$$, is
A
$$2.35s$$
B
$$4.9s$$
C
$$14.7s$$
D
$$29.4s$$
2
GATE ME 1992
+2
-0.6
Two rods, one of length $$L$$ and the other of length $$2L$$ are made of the same material and have the same diameter. The two ends of the longer rod are maintained at $${100^ \circ }C.$$ One end of the shorter end is maintained at $${100^ \circ }C.$$ while the other end is insulated. Both the rods are exposed to the same environment at $${40^ \circ }C.$$ The temperature at the insulated end of the shorter rod is measured to be $${55^ \circ }C.$$ The temperature at the mid-point of the longer rod would be
A
$${40^ \circ }C.$$
B
$${50^ \circ }C$$
C
$${55^ \circ }C$$
D
$${100^ \circ }C$$
GATE ME Subjects
Engineering Mechanics
Machine Design
Strength of Materials
Heat Transfer
Production Engineering
Industrial Engineering
Turbo Machinery
Theory of Machines
Engineering Mathematics
Fluid Mechanics
Thermodynamics
General Aptitude
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