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This section includes 21 Mcqs, each offering curated multiple-choice questions to sharpen your Physics knowledge and support exam preparation. Choose a topic below to get started.
1. |
Theoretically, a four stroke cycle engine should develop __________ power as that of a two stroke cycle engine. |
A. | double |
B. | half |
C. | same |
D. | four times |
Answer» C. same | |
2. |
The energy released during the fission of one atom of Uranium – 235 in million electron volts is about |
A. | 200 |
B. | 300 |
C. | 100 |
D. | 400 |
Answer» B. 300 | |
3. |
In a four stroke cycle diesel engine, the exhaust valve |
A. | opens at bottom dead centre and closes at top dead centre |
B. | opens at 60° after top dead centre and closes at 10° before top dead centre |
C. | opens at 30° before bottom dead cnetre and closes at 10° after top dead centre |
D. | may open and close anywhere |
Answer» D. may open and close anywhere | |
4. |
Morse test is used to determine the I.P. of a |
A. | four stroke engine |
B. | single cylinder diesel engine |
C. | single cylinder petrol engine |
D. | multi-cylinder engine |
Answer» E. | |
5. |
The working pressure and temperature inside the cylinder of an internal combustion engine is __________ as compared to a steam engine. |
A. | very low |
B. | very high |
C. | high |
D. | low |
Answer» C. high | |
6. |
A moderator |
A. | absorbs neutrons |
B. | accelerates neutrons |
C. | does not absorb neutrons |
D. | none of these |
Answer» D. none of these | |
7. |
The advancing of spark timing in spark ignition engines will __________ knocking tendency. |
A. | none of these |
B. | reduce |
C. | increase |
D. | not effect |
Answer» D. not effect | |
8. |
The correct mixture strength (by weight) for petrol is about |
A. | 14.6:1 |
B. | 22.6:1 |
C. | 20.4:1 |
D. | 18.5:1 |
Answer» B. 22.6:1 | |
9. |
The inlet valve of a four stroke cycle internal combustion engine remains open for |
A. | 130° |
B. | 180° |
C. | 270° |
D. | 230° |
Answer» E. | |
10. |
Supercharging __________ the power developed by the engine. |
A. | all of these |
B. | increases |
C. | decreases |
D. | has no effect on |
Answer» C. decreases | |
11. |
Which of the following statement is correct regarding petrol engines? |
A. | all of the above |
B. | The fuel supplied to the engine cylinder is mixed with necessary amount of air and the mixture in ignited with the help of a spark plug. |
C. | The fuel is first evaporated after passing through a carburettor and is mixed with air before ignition. |
D. | A fine fuel spray mixed with air is ignited by the heat of compression which is at a high pressure. |
Answer» C. The fuel is first evaporated after passing through a carburettor and is mixed with air before ignition. | |
12. |
The colour of exhaust from diesel engine is generally. |
A. | bluish |
B. | A. white |
C. | black |
D. | violent |
Answer» D. violent | |
13. |
The knocking in spark ignition engines can be reduced by |
A. | none of these |
B. | increasing the engine speed |
C. | both (a) and (b) |
D. | retarding the spark |
Answer» D. retarding the spark | |
14. |
The maximum propulsive efficiency of a turbo-jet engine is at a speed of |
A. | 3000 km/h |
B. | 1000 km/h |
C. | 2000 km/h |
D. | 2400 km/h |
Answer» E. | |
15. |
In order to mix air and petrol in the required proportion and to supply it to the engine during suction stroke, then __________ is employed. |
A. | carburettor |
B. | fuel pump |
C. | injector |
D. | none of these |
Answer» B. fuel pump | |
16. |
Which one of the following event would reduce volumetric efficiency of a vertical compression ignition engine ? |
A. | inlet valve opening before top dead centre |
B. | exhaust valve closing after top dead centre |
C. | inlet valve closing before bottom dead centre |
D. | inlet valve closing after bottom dead centre |
Answer» D. inlet valve closing after bottom dead centre | |
17. |
A moderator, apart from its high neutron slowing power, and low non-productive neutron, should be |
A. | corrossion resistant |
B. | stable under nuclear radiation |
C. | good thermal conductor |
D. | all of these |
Answer» E. | |
18. |
The delay period in compression ignition engines depends upon |
A. | nature of the fuel mixture strength |
B. | relative velocity between the fuel injection and air turbulence pressure of residual gases |
C. | temperature and pressure in the cylinder at the time of injection |
D. | all of the above |
Answer» E. | |
19. |
The frictional power (F.P.) is given by |
A. | F.P. = I.P. - B.P. |
B. | F.P. = B.P. - I.P. |
C. | F.P. = B.P./I.P. |
D. | F.P. = I.P./B.P. |
Answer» B. F.P. = B.P. - I.P. | |
20. |
The nuclear radiators produced in a reactor which must be sheilded are |
A. | electrons |
B. | none of these |
C. | α, β and γ rays |
D. | neutron and gamma rays |
Answer» E. | |
21. |
he material most commonly used for sheilding is |
A. | lead |
B. | carbon |
C. | concrete |
D. | all of these |
Answer» D. all of these | |