Assertion (A): Energy grade line lies above the hydraulic grade line a...
Assertion (A): Energy grade line lies above the hydraulic grade line and is always parallel to it.
Reason (R): The vertical difference between energy grade line and hydraulic grade line is equal to the velocity head.
The correct answer is option 'A', which means both the assertion and the reason are individually true and the reason is the correct explanation of the assertion. Let's break down the explanation for better understanding.
Energy Grade Line (EGL):
The energy grade line represents the total energy of the fluid at different points along the flow path. It is a graphical representation that shows the sum of the pressure head, elevation head, and velocity head at each point.
Hydraulic Grade Line (HGL):
The hydraulic grade line represents the pressure head of the fluid at different points along the flow path. It is a graphical representation that shows the pressure head and elevation head at each point, neglecting the velocity head.
Relationship between EGL and HGL:
1. The energy grade line (EGL) is always above the hydraulic grade line (HGL). This is because the EGL includes the velocity head, which is not considered in the HGL.
2. The EGL and HGL are parallel to each other. This is because the vertical difference between the EGL and HGL is equal to the velocity head.
Explanation of Assertion and Reason:
Assertion (A) states that the energy grade line lies above the hydraulic grade line and is always parallel to it. This is true because the EGL includes the velocity head, which adds to the total energy of the fluid. As a result, the EGL will always be above the HGL.
Reason (R) states that the vertical difference between the EGL and HGL is equal to the velocity head. This is also true because the EGL represents the total energy, including the velocity head, whereas the HGL neglects the velocity head. The difference between the two lines represents the velocity head.
Conclusion:
In conclusion, the energy grade line lies above the hydraulic grade line and is always parallel to it. The vertical difference between the EGL and HGL is equal to the velocity head. Therefore, both the assertion and the reason are individually true, and the reason is the correct explanation of the assertion.
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