The minimum work required for a three stage reciprocating air compressor is ________ the work required for each stage.

The inter-cooler pressure, for minimum work required, for a two stage reciprocating air compressor, is given by (where p₁ = Intake pressure of air, p₂ = Inter-cooler pressure and p₃ = Delivery pressure of air)

A

$${{\text{p}}_2} = {{\text{p}}_1} \times {{\text{p}}_3}$$

B

$${{\text{p}}_2} = \frac{{{{\text{p}}_1}}}{{{{\text{p}}_3}}}$$

C

$${{\text{p}}_2} = \sqrt {{{\text{p}}_1} \times {{\text{p}}_2}} $$

D

$${{\text{p}}_2} = \frac{{{{\text{p}}_3}}}{{{{\text{p}}_1}}}$$

In a single stage, single acting reciprocating air compressor, without clearance, the work-done on the air during isentropic compression is ________ the heat required to raise the temperature of air from T₁ to T₂ at a constant pressure.

A

Equal to

B

Less than

C

Greater than

D

None of these

Which of the following statements are true/false?
1. A minimum rate of wages for the time spent by employees for the production of output is minimum time rate.
2. Minimum piece rate is the rate based on the quantity of the output employees have produced.
3. The guaranteed time rate is a minimum rate of remuneration to apply in the case of employees employed on piece work for the purpose of securing to such employees a minimum rate of wages on a time work basis.
4. A minimum rate of remuneration to apply in the case of employees employed on piece work for the purpose of securing to such employees a minimum rate of wages on a time work basis is overtime rate.

A

1, 2, 3 and 4 are true

B

1, 3 are true and 2, 4 are false

C

2, 4 are true and 1, 3 are false

D

3, 4 are true and 2, 1 are false

If p₁, is the pressure of air entering the L.P. cylinder and p₂ is the pressure of air leaving the L.P. cylinder (or inter-cooler pressure), then the ratio of cylinder diameters for a single acting, two stage reciprocating air compressor with complete intercooling is given by (where D₁ = Diameter of L.P. cylinder and D₂ = Diameter of H.P. cylinder)

A

$$\frac{{{{\text{D}}_1}}}{{{{\text{D}}_2}}} = {{\text{p}}_1}{{\text{p}}_2}$$

B

$$\frac{{{{\text{D}}_1}}}{{{{\text{D}}_2}}} = \frac{{{{\text{p}}_1}}}{{{{\text{p}}_2}}}$$

C

$$\frac{{{{\text{D}}_1}}}{{{{\text{D}}_2}}} = \frac{{{{\text{p}}_2}}}{{{{\text{p}}_1}}}$$

D

None of these

In a single stage, single acting reciprocating air compressor, without clearance volume, the work-done is minimum during

A

Isothermal compression

B

Isentropic compression

C

Polytropic compression

D

None of these

If p₁ is the pressure of air entering the L.P. cylinder and p₃ is the pressure of air leaving the H.P. cylinder, then the ratio of cylinder diameters for a single acting, two stage reciprocating compressor with complete intercooling is given by

A

$$\frac{{{{\text{D}}_1}}}{{{{\text{D}}_2}}} = {\left( {{{\text{p}}_1}{{\text{p}}_3}} \right)^{\frac{1}{2}}}$$

B

$$\frac{{{{\text{D}}_1}}}{{{{\text{D}}_2}}} = {\left( {\frac{{{{\text{p}}_1}}}{{{{\text{p}}_3}}}} \right)^{\frac{1}{4}}}$$

C

$$\frac{{{{\text{D}}_1}}}{{{{\text{D}}_2}}} = {\left( {{{\text{p}}_1}{{\text{p}}_3}} \right)^{\frac{1}{4}}}$$

D

$$\frac{{{{\text{D}}_1}}}{{{{\text{D}}_2}}} = {\left( {\frac{{{{\text{p}}_3}}}{{{{\text{p}}_1}}}} \right)^{\frac{1}{4}}}$$

In a single stage, single acting reciprocating air compressor without clearance volume, the work-done is maximum during

A

Isothermal compression

B

Isentropic compression

C

Polytropic compression

D

None of these

The primary unbalanced force due to inertia of reciprocating parts in a reciprocating engine is given by (where m = Mass of reciprocating parts, $$\omega $$ = Angular speed of crank, r = Radius of crank, $$\theta $$ = Angle of inclination of crank with the line of stroke and n = Ratio of the length of connecting rod to radius of crank)

A

$${\text{m}}{\omega ^2}{\text{r}}\sin \theta $$

B

$${\text{m}}{\omega ^2}{\text{r}}\cos \theta $$

C

$${\text{m}}{\omega ^2}{\text{r}}\frac{{\sin 2\theta }}{{\text{n}}}$$

D

$${\text{m}}{\omega ^2}{\text{r}}\frac{{\cos2\theta }}{{\text{n}}}$$

The secondary unbalanced force due to inertia of reciprocating parts in a reciprocating engine is given by (where m = Mass of reciprocating parts, $$\omega $$ = Angular speed of crank, r = Radius of crank, $$\theta $$ = Angle of inclination of crank with the line of stroke and n = Ratio of the length of connecting rod to radius of crank)

A

$${\text{m}}{\omega ^2}{\text{r}}\sin \theta $$

B

$${\text{m}}{\omega ^2}{\text{r}}\cos \theta $$

C

$${\text{m}}{\omega ^2}{\text{r}}\frac{{\sin 2\theta }}{{\text{n}}}$$

D

$${\text{m}}{\omega ^2}{\text{r}}\frac{{\cos2\theta }}{{\text{n}}}$$

Find the inertia force of reciprocating parts of an engine, given mass of the reciprocating parts 200 kg and acceleration of reciprocating parts is 120 m/s2.

A

24000 kg-m/s2

B

25000 kg-m/s2

C

23000 kg-m/s2

D

26000 kg-m/s2

The minimum work required for a three stage reciprocating air compressor is ________ the work required for each stage.

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