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4 years ago

Any change in the system from one equilibrium state to another is called: A) Path B) Process C) Cycle D) None of the above

Engineering

1 answer:

dexar [7]4 years ago

7 0

Answer:

B) Process

Explanation:

In thermodynamics a process is a passage of a thermodynamic system from an initial to a final state of thermodynamic equilibrium.

A thermodynamic process path is the series of states through which a system passes from an initial to a final state.

Cycle is a process in which initial and final state are identical.

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A thin-walled tube with a diameter of 6 mm and length of 20 m is used to carry exhaust gas from a smoke stack to the laboratory

Molodets [167]

Answer:

Explanation:

Mean temperature is given by

$T_mean = \frac{T_i + T_ \infinity}{2}\\\\T_mean = \frac{200 + 15}{2}$

Tmean = (Ti + T∞)/2

$T_mean = 107.5^{0}$

Tmean = 107.5⁰C

Tmean = 107.5 + 273 = 380.5K

Properties of air at mean temperature

v = 24.2689 × 10⁻⁶m²/s

α = 35.024 × 10⁻⁶m²/s

$\mu$ = 221.6 × 10⁻⁷N.s/m²

$\kappa$ = 0.0323 W/m.K

Cp = 1012 J/kg.K

Pr = v/α = 24.2689 × 10⁻⁶/35.024 × 10⁻⁶

= 0.693

Reynold's number, Re

Pv = 4m/πD²

where Re = (Pv * D)/ $\mu$

Substituting for Pv

Re = 4m/(πD $\mu$ )

= (4 x 0.003)/( π × 6 ×10⁻³ × 221.6 × 10⁻⁷)

= 28728.3

Since Re > 2000, the flow is turbulent

For turbulent flows, Use

Dittus - Doeltr correlation with n = 0.03

Nu = 0.023Re⁰⁸Pr⁰³ = (h₁D)/k

(h₁ × 0.006)/0.0323 = 0.023(28728.3)⁰⁸(0.693)⁰³

(h₁ × 0.006)/0.0323 = 75.962

h₁ = (75.962 × 0.0323)/0.006

h₁ = 408.93 W/m².K

4 0

3 years ago

Two technicians are discussing the intake air temperature (IAT) sensor. Technician A says that the computer uses the IAT sensor

mart [117]

Both the technicians are correct.

Explanation

Intake air temperature sensor is used in engines of vehicles to monitor the temperature of air entering the engine.

They are basically made of thermistors whose electrical resistance changes according to temperature.

Depending upon the reading and accuracy of intake air temperature sensor, the power-train control module (PCM) will decide about the air and fuel mixture ratio in the engine.

The hot air in engine requires less fuel to operate the engine parts while cold air requires more fuel to operate the engine.

The ratio of air and fuel mixture should be maintained in the engine and it is done by PCM only after getting the input from IAT. So technician B is saying correct.

Also the IAT works as a backup to support the engine coolant temperature sensor by the computer.

As the IAT checks the temperature of outside air, it will help to change the coolant temperature of the engine based on the environment.

Thus technician A is also correct. So both the technicians are correct.

6 0

3 years ago

What is the minimum efficiency of a functioning current-model catalytic converter? a. 60% b. 75% c. 80% d. 90%

slamgirl [31]

Answer:

d. 90%

Explanation:

As we know that internal combustion engine produce lot's of toxic gases to reduce these toxic gases in the environment a device is used and this device is know as current modeling converter.

Generally the efficiency of current model catalytic converter is more than 90%.But the minimum efficiency this converter is 90%.

So option d is correct.

d. 90%

7 0

3 years ago

Choose the person who best completes each statement.

victus00 [196]

The exercise is about finding the missing medical terms from the list below.. See the sentences below for the missing words.

<h3>What are the completed sentences?</h3>

The outbreak and spread of epidemic diseases, such as swine flu, are tracked by a Public Health Surveillance Team.
The person who would use equipment to show an image of a baby before birth is a Diagnostic Medical Sonographer.
The education to become a Medical Practitioner requires more than four years of college.
When a water source becomes contaminated with an illness-causing bacteria, a Microbiologist could be brought in to study how to get rid of the microorganisms.

Learn more about medical terms at;
brainly.com/question/759368
#SPJ1

7 0

2 years ago

Read 2 more answers

Express the following quantities to the nearest standard prefix using no more than three digits.(a) 20,000,000 Hz(b) 1025 W(c) 0

bija089 [108]

Answer:

(a) 20 MHz

(b) 1.025 KW

(d) 33 pF

Explanation:

(a) 20,000,000 Hz = 20 x 10^6 Hz = 20 Mega Hz = 20 MHz

(b) 1025 W = 1.025 x 10^3 W = 1.025 Kilo W = 1.025 KW

(d) 33 x10^(-12)F = 33 pico F = 33 pF

8 0

4 years ago