**1. Pascal-second is the unit of**

a) pressure

b) kinematic viscosity

c) dynamic viscosity

d) surface tension

**Ans: c**

**2. An ideal fluid is**

a) one which obeys Newton’s law of viscosity

b) frictionless and incompressible

c) very viscous

d) frictionless and compressible

**Ans: b**

**3. The unit of kinematic viscosity is**

a) gm/cm-sec2

b) dyne-sec/cm2

c) gm/cm2-sec

d) cm2/sec

**Ans: d**

**4. If the dynamic viscosity of a fluid is 0.5 poise and specific gravity is 0.5, then the kinematic viscosity of that fluid in stokes is**

a) 0.25

b) 0.50

c) 1.0

d) none of the above

**Ans: c**

**5. The viscosity of a gas**

a) decreases with increase in temperature

b) increases with increase in temperature

c) is independent of temperature

d) is independent of pressure for very high pressure intensities

**Ans: b**

**6. Newton’s law of viscosity relates**

a) intensity of pressure and rate of angular deformation

b) shear stress and rate of angular deformation

c) shear stress, viscosity and temperature

d) viscosity and rate of angular deformation

**Ans: b**

**7. An open tank contains 1 m deep water with 50 cm depth of oil of specific gravity 0.8 above it. The intensity of pressure at the bottom of tank will be**

a) 4 kN/m2

b) 10 kN/m2

c) 12 kN/m2

d) 14 kN/m2

**Ans: d**

**8. The position of center of pressure on a plane surface immersed vertically in a static mass of fluid is**

a) at the centroid of the submerged area

b) always above the centroid of the area

c) always below the centroid of the area

d) none of the above

**Ans: c**

**9. The total pressure on a plane surface inclined at an angle 9 with the horizontal is equal to**

a) PA

b) pA sin 9

c) pA cos 9

d) pA tan 9

where p is pressure intensity at centroid of area and A is area of plane surface.

**Ans: a**

**10. A vertical rectangular plane surface is submerged in water such that its top and bottom surfaces are 1.5 m and 6.0 m res-pectively below the free surface. The position of center of pressure below the free surface will be at a distance of**

a) 3.75 m

b) 4.0 m

c) 4.2m

d) 4.5m

**Ans: c**

**11. Centre of buoyancy always**

a) coincides with the centre of gravity

b) coincides with the centroid of the volume of fluid displaced

c) remains above the centre of gravity

d) remains below the centre of gravity

**Ans: b**

**12. If the weight of a body immersed in a fluid exceeds the buoyant force, then the body will**

a) rise until its weight equals the buoyant force

b) tend to move downward and it may finally sink

c) float

d) none of the above

**Ans: b**

**13. Metacentric height for small values of angle of heel is the distance between the**

a) centre of gravity and centre of buoy-ancy

b) centre of gravity and metacentre

c) centre of buoyancy and metacentre

d) free surface and centre of buoyancy

**Ans: b**

**14. A floating body is said to be in a state of stable equilibrium**

a) when its metacentric height is zero

b) when the metacentre is above the centre of gravity

c) when the metacentre is below the centre of gravity

d) only when its centre of gravity is below its centre of buoyancy

**Ans: b**

**15. The increase in meta centric height**

i) increases stability

ii) decreases stability

iii) increases comfort for passengers

iv) decreases comfort for passengers

The correct answer is

a) (i) and (iii)

b) (i)and(iv)

c) (ii) and (iii)

d) (ii) and (iv)

**Ans: b**

**16. A rectangular block 2 m long, 1 m wide and 1 m deep floats in water, the depth of immersion being 0.5 m. If water weighs 10 kN/m3, then the weight of the block is**

a) 5kN

b) lOkN

c) 15 kN

d) 20 kN

**Ans: b**

**17. The point in the immersed body through which the resultant pressure of the liquid may be taken to act is known as**

a) center of gravity

b) center of buoyancy

c) center of pressure

d) metacentre

**Ans: c**

**18. If a vessel containing liquid moves downward with a constant acceleration equal to ‘g’ then**

a) the pressure throughout the liquid mass is atmospheric

b) there will be vacuum in the liquid

c) the pressure in the liquid mass is greater than hydrostatic pressure

d) none of the above

**Ans: a**

**19. When a liquid rotates at a constant angular velocity about a vertical axis as a rigid body, the pressure intensity varies**

a) linearly with radial distance

b) as the square of the radial distance

c) inversely as the square of the radial distance

d) inversely as the radial distance

**Ans: b**

**20. An open cubical tank of 2 m side is filled with water. If the tank is rotated with an acceleration such that half of the water spills out, then the acceleration is equal to**

a) g/3

b) g/2

c) 2g/3

d) g

**Ans: d**

**21. A right circular cylinder open at the top is filled with liquid and rotated about its vertical axis at such a speed that half the liquid spills out, then the pressure intensity at the center of bottom is**

a) zero

b) one-fourth its value when cylinder was full

c) one-half its value when cylinder was full

d) cannot be predicted from the given data

**Ans: a**

**22. The horizontal component of force on a curved surface is equal to the**

a) product of pressure intensity at its centroid and area

b) force on a vertical projection of the curved surface

c) weight of liquid vertically above the curved surface

d) force on the horizontal projection of the curved surface

**Ans: b**

**23. A closed tank containing water is moving in a horizontal direction along a straight line at a constant speed. The tank also contains a steel ball and a bubble of air. If the tank is decelerated horizontally, then**

i) the ball will move to the front

ii) the bubble will move to the front

iii) the ball will move to the rear

iv) the bubble will move to the rear

Find out which of the above statements are correct ?

a) (i) and (ii)

b) (i)and(iv)

c) (ii) and (iii)

d) (iii) and (iv)

**Ans: b**

**24. The eddy viscosity for turbulent flow is**

a) a function of temperature only

b) a physical property of the fluid.

c) dependent on the flow

d) independent of the flow

**Ans: c**

**25. Flow at constant rate through a tapering pipe is**

i) steady flow

ii) uniform flow

iii) unsteady flow

iv) non-uniform flow

The correct answer is

a) (i) and (ii)

b) (i)and(iv)

c) (ii) and (iii)

d) (ii) and (iv)

**Ans: b**