27. Two rollers of diameters Di (in mm) and D2 (in mm) are used to measure the internal taper angle in the V-groove of a machined component. The heights H (in mm) and H2 (in mm) are measured by using a height gauge after inserting the rollers into the same V-groove as shown in the figure. D H a D, H D > D Which one of the following is the correct relationship to evaluate the angle a as shown in the figure? (A) cosec= (H-H)-(D-D) 2(D - D) 2 (B) sin = (H-H) (D-D) (C) cosa: (D-D) 2(H-H)-2(D - D) (D) sin = (D-D) - 2(H H)-(D - D) 28. Consider a flow through a nozzle, as shown in the figure below: 1 stream line P1 V1 A = 0.2m 2 P2 Patm V = 50 m/s A = 0.02 m Wi The air flow is steady, incompressible and inviscid. The density of air is 1.23 kg/m. The pressure difference (pi - Patm) is. kPa (round off to 2 decimal places).