A Heat-Conducting Rod, 0 $0.70 \mathrm {~m}$ Long Both Sections Have a Cross-Sectional Area Of in Insulation

question 108

Multiple Choice

A heat-conducting rod, 0.90 m long and wrapped in insulation, is made of an aluminum section that is 0.20 m long and a copper section that is $0.70 \mathrm {~m}$ long. Both sections have a cross-sectional area of $0.00040 \mathrm {~m} ^ { 2 }$ The aluminum end and the copper end are maintained at temperatures of $30 ^ { \circ } \mathrm { C }$ and $230 ^ { \circ } \mathrm { C }$ respectively. The thermal conductivities of aluminum and copper are 205 W/m ∙ K (aluminum) and 385 W/m ∙ K (copper) . What is the temperature of the aluminum-copper junction in the rod with steady state heat flow?

• A) 100°C
• B) 93°C
• C) 86°C
• D) 80°C
• E) 74°C

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Definitions:

Production Possibilities Curve

A graph that shows the maximum number of possible units of two commodities that a economy can produce with available resources and technology.

Marginal Benefit

The incremental gain in happiness or usefulness obtained through consuming an extra unit of a good or service.

Marginal Cost

Marginal cost is the cost incurred by producing one additional unit of a product or service, emphasizing the concept of variable costing.

Resource Allocation

The process of allocating resources, including capital, labor, and materials, among competing uses or projects in an efficient manner.