##### Q41. For sub-sonic flow, if the area of flow increases

(a) velocity is constant
(b) velocity increases
(c) velocity decreases
(d) none of the above.

Ans:  (c) velocity decreases

##### Q42. For super-sonic flow, if the area of flow increases, then

(a) velocity decreases
(b) velocity increases
(c) velocity is constant
(d) none of the above.

Ans:  (b) velocity increases

##### Q43. The depth of flow at which specific energy is minimum is called

(a) normal depth
(b) critical depth
(c) alternate depth
(d) none of the above.

Ans:  (b) critical depth

##### Q44. For a circular channel, the wetted perimeter is given by

(a) Rθ/2
(b) 3Rθ
(c) 2Rθ
(d) Rθ
where R = Radius of circular channel and θ = Half the angle subtended by the water surface
at the centre.

Ans:  (c) 2Rθ

##### Q45. A most economical section is one which for a given cross-sectional area, slope of bed (i) and co-efficient of resistance has

(a) maximum wetted perimeter
(b) maximum discharge
(c) maximum depth of flow
(d) none of the above.

Ans:  (b) maximum discharge

##### Q46. Specific speed of a turbine is defined as the speed of the turbine which

(a) produces unit power at unit head
(b) produces unit power at unit discharge
(c) delivers unit discharge at unit head
(d) delivers unit discharge at unit power.

Ans:  (a) produces unit power at unit head

##### Q47.The drag force exerted by a fluid on a body immersed in the fluid is due to

(a) pressure and viscous force
(b) pressure and gravity forces
(c) pressure and turbulence forces
(d) none of the above.

Ans:  (a) pressure and viscous force

(a) x4/5
(b) x1/2
(c) x1/5
(d) x3/5

Ans:  (b) x1/2

(a) x4/5
(b) x1/2
(c) x1/5
(d) x3/5

Ans:  (a) x4/5

##### Q50. The separation of boundary layer takes place in case of

(a) negative pressure gradient
(b) positive pressure gradient
(c) zero pressure gradient
(d) none of the above.

Ans:  (b) positive pressure gradient

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##### Read More Sections of Automobile Engineering

Each section contains maximum 80 Questions. To practice more questions visit other sections.

Hydraulics and Fluid mechanics MCQ-Section-1

Hydraulics and Fluid mechanics MCQ-Section-2

Hydraulics and Fluid mechanics MCQ-Section-3

Hydraulics and Fluid mechanics MCQ-Section-4

Hydraulics and Fluid mechanics MCQ-Section-5