Related Questions

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 $${\text{m}}{\omega ^2}{\text{r}}\frac{{\cos2\theta }}{{\text{n}}}$$
Reciprocating pumps compared to centrifugal pumps
A Deliver liquid at uniform pressure
B Can handle slurries more efficiently
C Are not subject to air binding
D Can be operated with delivery valve closed
Centrifugal pumps as compared to reciprocating pumps
A Run at a lower speed for the same discharge
B Do not need priming
C Deliver fluid with pulsating/fluctuating discharge
D Can be run with discharge line valve closed for a short interval
The volumetric efficiency for reciprocating air compressors is about
A 10 to 40%
B 40 to 60%
C 60 to 70%
D 70 to 90%
Clearance volume in actual reciprocating compressors is essential
A To accommodate Valves in the cylinder head
B To provide cushioning effect
C To attain high volumetric efficiency
D To provide cushioning effect and also to avoid mechanical bang of piston with cylinder head
The reciprocating refrigerant compressors are very suitable for
A Small displacements and low condensing pressures
B Large displacements and high condensing pressures
C Small displacements and high condensing pressures
D Large displacements and low condensing pressures
Which of the following statement is correct as regard to centrifugal compressors?
A The flow of air is parallel to the axis of the compressor
B The static pressure of air in the impeller increases in order to provide centripetal force on the air
C The impeller rotates at high speeds
D The maximum efficiency is higher than multistage axial flow compressors
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

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