# Heat Transfer MCQ’s – Types of Flow

1 - Question

How many types of fluid flow are characterized in the realms of fluid mechanics?
a) 1
b) 2
c) 3
d) 4
Explanation: There are two types of flow i.e. laminar and turbulent flow.

2 - Question

In which fluid flow, the motion of fluid particles is irregular?
a) Turbulent
b) Laminar
c) One dimensional
d) Two dimensional
Explanation: It proceeds along erratic and unpredictable paths.

3 - Question

Following are the characteristics of turbulent flow (i) Eddying (ii) Sinuous (iii) Rectilinear Identify the correct option
a) ii and iii
b) i and iii
c) i, ii and iii
d) i and ii
Explanation: Obviously a turbulent flow is eddying and sinuous rather than rectilinear in character.

4 - Question

The nature of the fluid flow is governed by the following parameters (i) Mean flow velocity (ii) Density of fluid (iii) Dynamic viscosity of the fluid Identify the correct statements
a) i and iii
b) i only
c) i, ii and iii
d) ii and iii
Explanation: Osborne Reynolds, an English scientist confirmed the existence of these two regimes experimentally.

5 - Question

The value of convective coefficient of air in case of free convection is
a) 3-7 W/m2 K
b) 3-4 W/m2 K
c) 8-9 W/m2 K
d) 9-9.5 W/m2 K
Explanation: In case of air, the value of convective coefficient is small i.e. 3 W/m2 K to 7 W/m2 K. This is due to presence of some moisture in air.

6 - Question

The fluid particles move in flat or curved un-mixing layers or streams and follow a smooth continuous path. This type of flow is known as
b) Stream flow
c) Turbulent flow
d) Laminar flow
Explanation: The paths of fluid movement are well defined so it is laminar flow.

7 - Question

The characteristic dimension d in the relation R E = V d p/δ is the equivalent diameter and is defined as how many times the cross-sectional flow area divided by the wetted perimeter
a) 7
b) 4
c) 1
d) 6
Explanation: It is defined as four times the equivalent diameter and is defined as how many times the cross-sectional flow area divided by wetted perimeter.

8 - Question

For a duct of rectangular cross-section with length l and breadth b, the value of d e is
a) l b / l + b
b) 2 l b
c) 2 l b / l + b
d) 4 l b / l + b
Explanation: d e = 4 (l) (b)/2 l + 2 b.

9 - Question

In many flow situations, the duct can be (i) Circular (ii) Rectangle (iii) Trapezoidal (iv) Annulus Identify the correct option
a) i and ii
b) i, ii, iii and iv
c) i, ii and iii
d) iii and iv
Explanation: In many flow situations, the duct is not circular but is a rectangle, trapezoidal or even annulus formed by a tube within another tube.

10 - Question

If an annulus has an inner diameter of d 1 and an outer diameter of d 2 then the equivalent diameter is
a) 2 d 2 – d 1
b) d 2 – 2 d 1
c) d 1 – d 2
d) d 2 – d 1