subject
Engineering, 22.02.2020 02:30 ajam71501

A long electrical resistance wire of radius r.-0.25 cm has a thermal conductivity kwire-15 W/m-K. Heat is generated uniformly in the wire as a result of resistance heating at a constant rate of 0.5 W/cm3. The wire is covered with polyethylene insulation with a thickness of 0.25 cm and thermal conductivity of ks 0.4 W/m K. The outer surface of the insulation is subjected to free convection in air at 20°C and a convection heat transfer coefficient of 2 W/m2.K. Formulate the temperature profiles for the wire and the polyethylene insulation. Use the temperature profiles to determine the temperature at the interface of the wire and the insulation and the temperature at the center of the wire. The ASTM D1351 standard specifies that thermoplastic polyethylene insulation is suitable for use on electrical wire that operates at temperatures up to 75 C. Under these conditions, does the polyethylene insulation for the wire meet the ASTM D1351 standard?

ansver
Answers: 2

Another question on Engineering

question
Engineering, 04.07.2019 18:10
Courses that are developed by subject matter experts, internal or extemal to the college or university. these programs are marketed by the school (clo2) marks a)-vocational schools b)-vendor training c)-colleges & universities d)-continuing education programs
Answers: 2
question
Engineering, 04.07.2019 18:20
Prove the equivalence between the two statements of the 2nd law of thermodynamics (i.e., a violation of one statement leads to the violatio the other statement)
Answers: 2
question
Engineering, 04.07.2019 19:10
The short distance from the objective lens to the object causes problems at high magnification. which of the following is the most serious? a. cleaning the object surface b. positioning the object c. reflection from the object surface. d. illumination of the object
Answers: 1
question
Engineering, 04.07.2019 19:10
Agas contained within a piston-cylinder assembly e end nation about same energy states, 1 and 2, where pi 10 bar, v undergoes two processes, a and b, between the sam 0.1 m3, ui-400 kj and p2 1 bar, v2 1.0 m2, u2 200 kj: process a: process from 1 to 2 during which the pressure- volume relation is pv constant process b: constant-volume process from state 1 to a pressure of 2 bar, followed by a linear pressure-volume process to +20 0 state 2 kinetic and potential energy effects can be ignored. for each of the processes a and b, (a) sketch the process on p-v coordinates, (b) evaluate the work, in kj, and (c) evaluate process the heat transfer, in kj
Answers: 2
You know the right answer?
A long electrical resistance wire of radius r.-0.25 cm has a thermal conductivity kwire-15 W/m-K. He...
Questions
question
Mathematics, 27.08.2020 06:01
question
Biology, 27.08.2020 06:01
question
Chemistry, 27.08.2020 06:01
question
History, 27.08.2020 06:01
Questions on the website: 13722360