Answer: Flexible duct because, They also developed more than 1,000 safety criteria, some of which are... labelled goods bearing a silver UL sticker on the duct that defines this listing. ... lie in the research carried out by UL and, as a result, the authorized use of the code. Air Ducts are required to perform 15 separate tests.
Source: https://dundasjafine.com/ul-classification/
Answer:
metals, composite, ceramics and polymers.
Explanation:
The four categories of engineering materials used in manufacturing are metals, composite, ceramics and polymers.
i) Metals: Metals are solids made up of atoms held by matrix of electrons. They are good conductors of heat and electricity, ductile and strong.
ii) Composite: This is a combination of two or more materials. They have high strength to weight ratio, stiff, low conductivity. E.g are wood, concrete.
iii) Ceramics: They are inorganic, non-metallic crystalline compounds with high hardness and strength as well as poor conductors of electricity and heat.
iv) Polymers: They have low weight and are poor conductors of electricity and heat
Answer:
Explanation:
The heat transfer rate due to convection is calculated by this formula:
The output is determined by replacing terms:
Answer:
a) 512.5 KW/m2
b) 40.75 KW/m2
c) 2 KW/m2
Explanation:
Given data;
T_2 = 325 K
T_1 = 275 K
dx = 0.20 mm
a) for aluminium K = 205 W/m k
heat flux 
= 512.5 KW/m2
b) for AISI 316 stainless steel
k = 16.3 W/ m k
heat flux
= 40.75 KW/m2
C) for Concrete
k = 0.8 W/ m k
heat flux
= 2 KW/m2
