ME 410 - Spring 2011
Testl
Problem 1 - A 15 cm X 20 cm circuit board
houses 120 closely spaced 0.12 W logic
chips. Determine
1. the amount of heat dissipated in 10 h
in kWh.
2. the heat ﬂux on the surface of the
circuit board in W/rn2
_ Chips
15 cm
\

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ME410 FALL 2010 - TEST 3
USEFUL EQUATIONS ARE GIVEN BELOW THE
LAST PROBLEM.
Problem 1 - Water is boiled at 100°C
electrically by an 80-cm-long, 2-mm-
diameter horizontal resistance wire made of
chemically etched stainless steel. Determine
the rate of h

Test 2 ME 410, Fall 2011
Closed book and closed notes
Problem 1
A thick wood slab (k = 0.17 W/mK and = 1.28 x 10-7 m2/s) that is initially at a uniform
temperature of 25C is exposed to hot gases at 550C for a period of 5 min. The heat transfer coefficient

Test 3 ME 410, Fall 2011
Closed book and closed notes
Problem 1
Consider a 10-m long smooth rectangular tube, with a = 50 mm and b = 25 mm, that is
maintained at a constant surface temperature. Liquid water enters the tube at 20C with a mass flow
rate of

Test 1 ME 410, Fall 2011
Closed book and closed notes
Problem 1
Consider a sealed 20-cm-high electronic box whose base dimensions are 50 cm x 50 cm
placed in a vacuum chamber. The emissivity of the outer surface of the box is 0.95. If the electronic
compo