Air flows at the rate of 1.5 m3/s through a horizontal pipe with a gradually reducing cross- section as shown in the figure

Q. Air flows at the rate of 1.5 m³/s through a horizontal pipe with a gradually reducing cross- section as shown in the figure. The two cross-sections of the pipe have diameters of 400 mm and 200 mm. Take the air density as 1.2 kg/m³ and assume inviscid incompressible flow. The change in pressure ( p₂ – p₁ ) (in kPa) between sections 1 and 2 is

(A) -1.28                    (B) 2.56                      (C) -2.13                    (D) 1.28

Ans: -1.28