Câu hỏi trắc nghiệm

1. The correct units on viscosity are

(A)  kg/(s · m)

(B)  kg · m/s

(C)  kg · s/m

(D)  kg · m/s2

2. A vacuum of 25 kPa is measured at a location where the elevation is4000 m. The absolute pressure, in millimeters of mercury, is nearest

(A)  425 mm

(B)  375 mm

(C)  325 mm

(D)  275 mm

3. Afluid mass of 1500 kg occupies 2 m3.Its specific gravity is nearest

(A) 1.5

(B)  0.75

(C)  0.30

(D)  0.15

4. Aviscometer is composed of two 12-cm-long, concentric cylinders with radii 4 and 3.8 cm.The outer cylinder is stationary and the inner one rotates. If a torque of 0.046 N · m is measured on the inner cylinder at a rotational speed of 120 rpm, estimate the viscosity of the liquid. Neglect the contribution to the torque from the cylinder ends and assume a linear velocity profile.

(A)  0.127 N · s/m2

(B)  0.149 N · s/m2

(C)  0.161 N · s/m2

(D)  0.177 N · s/m2

5. A0.1-m3volume of water is observed to be 0.0982 m3 after a pressure is applied. What is that pressure?

(A)  37.8 MPa

(B)  24.2 MPa

(C)  11.7 MPa

(D)  8.62 MPa