GATE 2020 ME (ME2) – Question 59

Fluid Mechanics · Flow through pipes, head losses, bends and fittings · 2 marks · Numerical answer

Water of density 1000 kg/m³ flows in an inclined constant-diameter pipe. At A, speed = 3.2 m/s, pressure = 186 kPa and elevation = 24.5 m; at B, speed = 3.2 m/s, pressure = 260 kPa and elevation = 9.1 m. With g = 10 m/s², find frictional head loss (m), to one decimal.

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Correct answer: 7.9 to 8.1

Explanation

Velocity heads cancel. Total-head difference is(186000−260000)/(1000×10)+(24.5−9.1)=−7.4+15.4=**8.0 m**. A has the higher total head, despite its lower pressure, so the flow loses head fromA toB.