Which of the following statement is correct for steam turbines as compared to reciprocating steam engines?

Vacuum for reciprocating steam engines compared to steam turbines is

A

More

B

Equal

C

Less

D

Could be more or less depending on the size of plant

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

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

The Diesel engines as compared to petrol engines require

A

Bigger flywheel

B

Smaller flywheel

C

Same size of flywheel

D

No flywheel

The tractive force in a locomotive with two cylinders is given by (where c = Fraction of reciprocating parts per cylinder, m = Mass of reciprocating parts, $$\omega $$ = Angular speed of crank, r = Radius of crank and $$\theta $$ = Angle of inclination of crank to the line of stroke)

A

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

B

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

C

$$\left( {1 - {\text{c}}} \right){\text{m}}{\omega ^2}{\text{r}}\left( {\cos \theta - \sin \theta } \right)$$

D

$${\text{m}}{\omega ^2}{\text{r}}\left( {\cos \theta - \sin \theta } \right)$$

In a reciprocating engine, usually __________ of the reciprocating masses are balanced.

A

One-half

B

Two-third

C

Three-fourth

D

Whole

By fitting an air vessel to the reciprocating pump, there is always a saving of work done and subsequently saving of power. The saving in case of a double acting reciprocating pump is

A

39.2%

B

48.8%

C

84.8%

D

88.4%

By fitting an air vessel to the reciprocating pump, there is always a saving of work done and subsequently saving of power. This saving in case of a single acting reciprocating pump is

A

39.2%

B

48.8%

C

84.8%

D

88.4%

Steam turbines commonly used in steam power station are

A

condensing type

B

non-condensing type

C

both (A) and (B)

D

none of the above

In impulse turbines, when friction is neglected, the relative velocity of steam at outlet tip of the blade is _________ the relative velocity of steam at inlet tip of the blade.

A

Equal to

B

Less than

C

Greater than

D

None of these

Which of the following statement is correct for steam turbines as compared to reciprocating steam engines?

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