Explanation:
McLeod gauge:
It is used to measure very low pressure of gas.It measure gas pressure by the help of mercury(Hg).it measure absolute pressure of gas.
McLeod gauge on the principle of Boyle's law.Boyle's law state that ,at constant temperature the pressure of gas is directly proportional to its volume.From Boyle's law
A sample of gas is taken from vacuum then its pressure is measured by help Hg.
Answer:
a) Mechanical efficiency ()=63.15% b) Temperature rise= 0.028ºC
Explanation:
For the item a) you have to define the mechanical power introduced (Wmec) to the system and the power transferred to the water (Pw).
The power input (electric motor) is equal to the motor power multiplied by the efficiency. Thus, .
Then, the power transferred (Pw) to the fluid is equal to the flow rate (Q) multiplied by the pressure jump . So
.
The efficiency is defined as the ratio between the output energy and the input energy. Then, the mechanical efficiency is
For the b) item you have to consider that the inefficiency goes to the fluid as heat. So it is necessary to use the equation of the heat capacity but in a "flux" way. Calling <em>H</em> to the heat transfered to the fluid, the specif heat of the water and the density of the water:
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Finally, the temperature rise is:
Answer:
Work transfer is - 97.02 KJ. It means that work is given to the system.
Heat transfer = - 97.02 KJ . It means that heat is rejected from the system.
Explanation:
Given that
m= 3 kg
P₁=2 bar
T=T₁=T₂=30 °C
T=303 K
P₂=2.5 bar
PV= Constant
This is the isothermal process .
We know that work for isothermal process given as
For air
R= 0.287 KJ/Kg.K
Now by putting the values
W= - 97.02 KJ
So the work transfer is - 97.02 KJ. It means that work is given to the system.
We know that for ideal gas internal energy is the only function of temperature.The change in internal energy ΔU
ΔU = m Cv ΔT
Here ΔT= 0
So
ΔU =0
From first law of thermodynamics
Q= ΔU +W
ΔU = 0
Q= W
Q= - 97.02 KJ
Heat transfer = - 97.02 KJ . It means that heat is rejected from the system.