Answer:
The correct option is;
C. The flow of refrigerant to the evaporator became blocked
Explanation:
The function of the expansion valve is the reduction in the refrigerant pressure entering the evaporator so as to enable the desired change from liquid to gaseous state in the evaporator with the temperature of the high pressure refrigerant that enters into the expansion valve being warm
The expansion valve controls the liquid refrigerant flowing between the low and high pressure areas of the refrigerator
The expansion valve supplies the liquid refrigerant to the evaporator coil ensures a reduction in pressure of the refrigerant before the refrigerant enters the evaporator coil.
A piston-cylinder device contains 0.1 kg of hydrogen gas (PG model: cv=10.18, k = 1.4, R= 4.12 kJ/kg-K) at 1000 kPa and 300 K. The gas undergoes an expansion process and the final conditions are 500 kPa, 270 K. If 10 kJ of heat is transferred into the gas from the surroundings at 300 K, determine (a) the boundary work (Wb), and (b) the entropy generated (Sgen) during the process
Answer:
(a) 151.84 kJ
(b) 2.922 kJ/K
Explanation:
(a) The parameters given are;
Mass of hydrogen gas, H₂ = 0.1 kg = 100 g
Molar mass of H₂ = 2.016 g/mol
Number of moles of H₂ = 100/2.016 = 49.6 moles
V₁ = mRT/P = 0.1×4.12×300/1000 = 0.1236 m³
P₁/P₂ = (V₂/V₁)^k
V₂ = (P₁/P₂)^(1/k)×V₁ =0.1236 × (1000/500)^(1/1.4) = 0.3262 m³
Boundary work done = (V₂ - V₁)(P₂ + P₁)/2 = (0.3262 - 0.1236)*(500 + 1000)/2 = 151.84 kJ
(b) Entropy generated ΔS = Cv · ㏑(T₂/T₁) + R ·㏑(v₂/v₁)
=10.18 × ㏑(270/300) + 4.12 ·㏑(0.3262/0.1236) = 2.922 kJ/K.
The new Boeing 777 aircraft was designed and engineered by a group of Boeing employees from manufacturing, marketing, and engineering departments and by representatives of Boeing’s customers (major airlines such as United and American Airlines), all working closely together in an intensive effort. This design and engineering group for the 777 can be classified as_________.
Answer:
A cross-functional team
Explanation:
A cross-functional team are a customer centric collection of professionals with diverse area of expertise that come together to attain a common purpose by collaboration which aids in the maximization of effort, investment, and time in achieving customer satisfaction and the goals of the organization
The team can comprise members from different departments within the organization such as marketing, finance, safety and quality, human resources as well as operations.
A widebody aircraft
The Boeing 777 is accounted as a wide body aircraft because it has 2 isles and other aircraft have one like the Boeing 737 is not considered as widebody because it has only one isle and like the Airbus A330-900 is a competitor to the Boeing 777 and has 2 isles in the aircraft so it is considered a wide body aircraft.
Explain what a margin of safety is in driving as well as how it can help minimize risk.
Answer:
A safety margin is the space left between your vehicle and the next to provide room, time and visibility at every instant
Explanation:
A safety margin is defined as an allowance given between your vehicle and the next vehicle in front to provide enough room, visibility and time to move in a safe manner to prevent the occurrence of an accident at anytime the frontal vehicle suddenly stops or slows down
Safety margins help minimize risks in the following way
1) A common knowledge of safety margins, improves predictability among road users, thereby minimizing the risk traffic accidents caused due to late communication
2) The use of safety margins helps minimize the risk due to a change in driving conditions such as when the road becomes more slippery from being covered with fluid that is being wetted
3) Safety margin can help prevent the occurrence of an accident between vehicles due to failure of a car system, such as a punctured tire or failed breaking system
4) Safety margin helps to protect road users from the introduction of obstacles on the main roads such as ongoing road construction, broken down vehicles, road blockage by vehicles involved in an accident etc
5) Safety margin help protect road users from being involved in an accident due to the loss of driving focus of the driver of the frontal vehicle
what's the real power if Vrms = 100V, Irms = 2A, and the circuit has a power factor of 0.8?
Answer:
160 W
Explanation:
The relation is ...
Real Power = (pf)(V)(A)
= 0.8(100)(2) = 160 . . . . watts
Which material is used in a photovoltaic cell? A photovoltaic cell converts solar radiation into electric current using a thin sheet of____ like silicon.
Answer:
first on is silicon
Explanation:
Answer:
Silicon
Explanation:
Copper indium dieseline (CIS), cadmium telluride (CdTe), and thin-film silicon are certain polycrystalline thin film materials often used, whereas high-efficiency material such as gallium arsenide (GaAs) often comprise single-crystalline thin film materials3.