The ratio of the diameter of a circular section and the side of a square section hydraulically equivalent, is

In case of hydraulically smooth pipe, the resistance to flow depends only on the Reynolds number, whereas for a hydraulically rough pipe, the resistance to flow is governed by the relative roughness. Two pipes are said to have the same hydraulic roughness, when they have equal values of

A

Relative roughness

B

Absolute roughness

C

Friction co-efficient for flows at equal Reynold number

D

All of the above

The length of each side of square A is increased by 100 percent to make square B. Again the length of each side of square B is increased by 50 percent to make square C. By what percent is the area of square C greater than the sum of the areas of square A and B?

A

75%

B

80%

C

85%

D

90%

The length of each of square A is increased by 100 percent to make square B.Again the length of the each side of square B is increased by 50 peacent to make square C.By of the area df square A and B?

A

75%

B

80%

C

85%

D

90%

In a shell and tube heat exchanger having square pitch, the shell side equivalent diameter is given by (where, P = pitch, d = outside diameter of the tube)

A

$$\frac{{4\left( {{{\text{p}}^2} - \pi {{\text{d}}^2}/4} \right)}}{{\pi {\text{d}}}}$$

B

$$\frac{{{{\text{p}}^2} - \pi {{\text{d}}^2}/4}}{{\pi {\text{d}}}}$$

C

$$\frac{{4{{\text{p}}^2}}}{{\pi {\text{d}}}}$$

D

$$\frac{{\pi {\text{d}}}}{{4{{\text{p}}^2}}}$$

For annular flow of a fluid, the ratio of the equivalent diameter for pressure drop calculation to the equivalent diameter for heat transfer calculation is

A

$$\frac{{{{\text{d}}_1}}}{{{{\text{d}}_1} + {{\text{d}}_2}}}$$

B

$$\frac{{{{\text{d}}_2}}}{{{{\text{d}}_1} + {{\text{d}}_2}}}$$

C

$$\frac{{{{\text{d}}_1} + {{\text{d}}_2}}}{{{{\text{d}}_1}}}$$

D

$$\frac{{{{\text{d}}_1} + {{\text{d}}_2}}}{{{{\text{d}}_2}}}$$

For a given Reynolds number, in a hydraulically smooth pipe, further smoothening __________ the friction factor.

A

Brings about no further reduction of

B

Increases

C

Decreases

D

None of these

The friction factor for turbulent flow in a hydraulically smooth pipe

A

Depends only on Reynolds number

B

Does not depend on Reynolds number

C

Depends on the roughness

D

None of these

A pipe is defined as 'hydraulically smooth', if the friction factor

A

Is not a function of Reynolds number

B

For a given Reynolds number remains constant even on further smoothening of the pipe

C

Is zero irrespective of the Reynolds number

D

None of these

If D is the diameter of a circular sewer and D’ is the top horizontal diameter of an equivalent egg shaped section, the relationship which holds good, is

A

D’ = 0.64 D

B

D’ = 0.74 D

C

D’ = 0.84 D

D

D’ = 0.94 D

A small square region inside a larger square is shaded. The diagonal of the larger square is three times the diagonal of the small square in length. What fraction of the area of the larger square is not shaded?

A

1/9

B

1/3

C

2/3

D

8/9

The ratio of the diameter of a circular section and the side of a square section hydraulically equivalent, is

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