The surface of a long 1-mm diameter pure aluminum wire is exposed to 20 C ambient air having h = 35 W/m?
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The surface of a long 1-mm diameter pure aluminum wire is exposed to 20 C ambient
air having h = 35 W/m? . K . The temperature of the wire is initially the same as the
temperature of the ambient air. The wire has an electrical resistance per unit length of
R = 0.034 0/m and at time t=0 a 20 ampere current begins flowing through the wire.
a) Verify that heating the wire may be treated as a lumped-capacity process.
c) Find how long it takes for the temperature of the wire to reach 100 C (answer: 18 s).

The values of various properties of Aluminum are missing from the... View the full answer

Re= 0.034
I=20 A
Too = 20 0
5 mm
h = 35 w
Kaluminium = 237 W.
mik
mk
PAluminium = 2700 kg
(1 ) Let the length of the will be I'm
This wise can be considered as a cylinder.
Aluminium = 921 J
For it...

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