Consider the following statements: The volumetric efficiency of a reciprocating compressor can be improved by 1. decreasing the clearance volume 2. cooling the intake air 3. heating the intake air Which of the above statements is/are correct?

Consider the following statements for the appropriate context: 1. The Relative Humidity of air remains constant during sensible heating or cooling 2. The Dew Point Temperature of air remains constant during sensible heating or cooling 3. The total enthalpy of air remains constant during adiabatic cooling 4. It is necessary to cool the air below its Dew Point Temperature for dehumidifying Which of the above statements are correct?

A

1, 2 and 3

B

1, 2 and 4

C

3 and 4 only

D

2, 3 and 4

Consider the following statements for cooling towers: 1. Cooling tower is an artificial device used to cool the hot cooling water coming out of condenser more effectively. 2. The amount of water usually lost with induced draft cooling tower ranges from 5% to 6% by evaporation. 3. The amount of water usually lost with induced draft cooling tower ranges from 7% to 8% by drift losses. 4. The rate of evaporation of water and its cooling effect on the remaining water depends upon the relative humidity of air passing through the tower. Which of the above statements are correct?

A

1 and 4 only

B

1 and 3 only

C

2 and 3 only

D

1, 2, 3 and 4

If the clearance ratio for a reciprocating air compressor is 'K', then its volumetric efficiency is given by

A

$$1 - {\text{K}} + {\text{K}}{\left( {\frac{{{{\text{p}}_1}}}{{{{\text{p}}_2}}}} \right)^{\frac{1}{{\text{n}}}}}$$

B

$$1 + {\text{K}} - {\text{K}}{\left( {\frac{{{{\text{p}}_2}}}{{{{\text{p}}_1}}}} \right)^{\frac{1}{{\text{n}}}}}$$

C

$$1 - {\text{K}} + {\text{K}}{\left( {\frac{{{{\text{p}}_1}}}{{{{\text{p}}_2}}}} \right)^{\frac{{{\text{n}} - 1}}{{\text{n}}}}}$$

D

$$1 + {\text{K}} - {\text{K}}{\left( {\frac{{{{\text{p}}_2}}}{{{{\text{p}}_1}}}} \right)^{\frac{{{\text{n}} - 1}}{{\text{n}}}}}$$

In IC engine 1. the ideal air capacity of a two-stroke engine is the mass of air required to concurrently fill the total cylinder volume at inlet temperature and exhaust pressure 2. with increase in air-fuel ratio beyond the value for maximum power, there is a fall in power developed and this fall is more with higher values of air-fuel ratio. 3. the volumetric efficiency of the engine depends on the design of intake and exhaust manifold. Which of the above are correct?

A

1 and 2 only

B

1 and 3 only

C

2 and 3 only

D

1, 2 and 3

A gas engine has a swept volume of 300 cm³ and clearance volume of 25 cm³. Its volumetric efficiency is 0.88 and mechanical efficiency is 0.90. The volume of the mixture taken in per stroke is

A

248 cm³

B

252 cm³

C

264 cm³

D

286 cm³

Consider the following statements in respect of natural-draft cooling towers: 1) Theoretically the water can be cooled to even below the dry-bulb temperature of the induced air flow. 2) Nature-draft cooling towers are 100 m or more in height. 3) The inner and outer surfaces are surfaces of revolution of a segment of a hyperbola about the vertical axis-affording improved strength rather than any thermodynamic augmentation. Which of the above statements are correct?

A

1,2 and 3

B

1 and 2 only

C

1 and 3 only

D

2 and 3 only

Profits can be increased by
1. decreasing the selling price per unit.
2. increasing the selling price per unit.
3. decreasing the volume of sales.
4. increasing the volume of sales.
5. decreasing the fixed or variable expenses.
6. increasing the fixed or variable expenses.
7. giving more weightage for products having higher P/V ratio.
8. giving less weightage for products having higher P/V ratio.
Select the correct answer

A

1, 3, 5 and 7

B

2, 4, 6 and 8

C

2, 4, 5 and 7

D

1, 3, 6 and 8

Volumetric efficiency of a compressor without clearance volume

A

Increases with increase in compression ratio

B

Decreases with increase in compression ratio

C

Is not dependent upon compression ratio

D

May increase/decrease depending on compressor capacity

Volumetric efficiency of a compressor with clearance volume

A

Increases with increase in compression ratio

B

Decreases with increase in compression ratio

C

In not dependent upon compression ratio

D

May increase/decrease depending on compressor capacity

Consider the following statements :
In the first zone of production function
1. The APP is increasing and then decreasing
2. The MPP is increasing and then decreasing
3. TPP is increasing
4. APP is decreasing
Which of the above statements are correct

A

1 and 2

B

2 and 3

C

1 and 4

D

None of these

Consider the following statements: The volumetric efficiency of a reciprocating compressor can be improved by 1. decreasing the clearance volume 2. cooling the intake air 3. heating the intake air Which of the above statements is/are correct?

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